Algal (algae) oil

Algal oil (microalgae oil) · also called Algae oil, microalgal oil, vegan DHA, aceite de algas

Algal oil is an oil from algae that supplies DHA, and in some products EPA, without using fish. In small trials it raised blood DHA about as well as salmon or fish oil. It lowered triglycerides but also raised LDL cholesterol, and there is no trial showing it protects the heart. No source we read says whether people with fish allergy can use it, so ask a doctor or pharmacist.

General information, not medical advice. Last substantive update October 26, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

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About Algal (algae) oil

Algal oil is a fish-free source of DHA. Trials show it raises blood DHA like fish oil, but its blood-fat effects are mixed and no heart-outcome trial exists. Allergy and quality questions remain open.

What algal oil is

Algal oil comes from algae. NCCIH calls algal oils a vegetarian source of DHA and says some also contain EPA. People who avoid fish, including vegetarians and vegans, may look at it.

It is not the same as fish oil, cod liver oil or krill oil, which come from fish or krill, or as flaxseed oil, which supplies a different omega-3 called ALA. This page covers the algal supplement only; the others have their own pages.

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Food sources and why vegans come up

NCCIH names salmon, mackerel and tuna, shellfish and fish oil supplements as sources of EPA and DHA. Plant foods such as flaxseed, soybean and canola oils, chia seeds and walnuts supply ALA instead. The NHS vegan-diet page lists linseed oil, rapeseed oil, chia, hemp seeds and walnuts and does not mention algal oil.

A 2026 review of 45 studies found vegan diets go with lower blood EPA and DHA, and that algal-oil DHA improved DHA status. A study of 165 vegans found their average omega-3 index was similar to that of meat-eaters, so the gap is not the same everywhere. Amounts per portion of food were not researched here.

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What the research shows

Three small trials found algal oil raises blood DHA, similar to cooked salmon and fish oil. These measure blood levels, not health, and two come from makers of algal oil.

A review of 11 trials in healthy people found algal DHA lowered triglycerides but raised LDL and HDL cholesterol. A Cochrane review found fewer preterm births with omega-3 in general. One trial in older adults showed a modest memory gain, and two school trials in children did not agree. No trial of algal oil on heart attacks or strokes was found.

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Quality and labels

We found no study testing algal oil products for oxidation, contaminants or label accuracy. The label should show the DHA and EPA content, the other ingredients and the capsule shell. Capsule shells can contain animal ingredients, so check the label if that matters to you.

The one safety evaluation we read, in rats and in test-tube tests, found no harm from Schizochytrium algal oil. That is animal evidence only.

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At a glance

Traditional uses history, not proof

No traditional use is described in the sources read. It is a modern supplement made from cultured algae.
Sold as capsules or liquid, and added to some foods, as a vegetarian source of DHA

Studied for research

A fish-free source of DHA, high certainty
Raising blood DHA, moderate certainty
DHA status in vegans and vegetarians, moderate certainty
Triglycerides lower but LDL cholesterol higher, mixed
Pregnancy and breastfeeding, low certainty
Memory in older adults, low certainty
Children's reading and behaviour, mixed
Heart attacks, stroke, cystic fibrosis, eyes, mood and ADHD, insufficient evidence

Main compounds

DHA (docosahexaenoic acid)
EPA (eicosapentaenoic acid), in some products

Common forms

Capsules
Liquid oil
Foods fortified with algal oil (such as the snack bar tested in one trial)

Research links: 2008 trial: algal-oil capsules and cooked salmon (32 adults) · 2012 meta-analysis: algal DHA, triglycerides and cholesterol · 2025 trial: microalgal oil versus fish oil (74 adults) · 2026 review: vegetarian diets and omega-3 status · NCCIH: omega-3 supplements · Research Library · Genes & Biomarkers Library

What it is and its history

Accepted scientific name: Algal oil (an oil from microalgae, sold as a source of DHA and sometimes EPA)
Common names: Algal oil (English); Algae oil (English); Microalgal oil (English); Aceite de algas (Spanish)
Family or group: A microalgae-derived omega-3 oil. NCCIH lists algal oils with fish oil, fish liver oil, krill oil and flaxseed oil as types of omega-3 supplement.
Classification: Schizochytrium (one genus whose oil was safety-tested; other algae are also used)
Cultivation: Not described in the sources read.
Harvest and processing: Not described in the sources read.
Look-alikes and adulterants: Name: Fish oil; Note: Oil from the flesh of oily fish; supplies EPA and DHA. It has its own page.; Name: Krill oil; Note: Marine omega-3 with the fats carried as phospholipids (NCCIH). It has its own page.; Name: Cod liver oil; Note: Fish liver oil that also carries vitamins A and D (NCCIH). It has its own page.; Name: Flaxseed oil and other plant oils; Note: Supply ALA, a different omega-3, not DHA or EPA (NCCIH). See the plant omega-3 page.
Sustainability and conservation: Not assessed.

What is inside, and how it may work

What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.

Main compounds

Compound	Family	Where it is concentrated	Activity studied	Level of evidence
DHA (docosahexaenoic acid)	long-chain omega-3 fatty acid	Algal oil Varies by product; read the label.	The main fat in algal oil. Algal-oil DHA raised blood DHA similar to salmon or fish oil in small trials. ^{19 5 6}	Human data
EPA (eicosapentaenoic acid)	long-chain omega-3 fatty acid	Some algal oils Present in some products only (NCCIH); read the label.	Raised in blood along with DHA in the 2025 trial of microalgal oil. ^{19 6}	Human data

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
DHA absorption into blood fats and red blood cells	Not described in the sources read	Algal-oil DHA was taken up into plasma phospholipids and red blood cells, in a straight line with the amount taken (2007 trial). ^{4 5}	Human data
Blood fats (triglycerides, LDL, HDL)	Not described in the sources read	Triglycerides fell and LDL and HDL cholesterol rose in the pooled trials. The reason for the LDL rise was not given in the abstract. ⁷	Human data

Absorption, metabolism and elimination

Absorption: Blood DHA rose within 2 weeks in the salmon-comparison trial and was non-inferior to fish oil at 6 and 14 weeks.
Distribution: DHA entered red blood cells and breast milk in the trials read.
Metabolism: Not described.
Elimination: Not described.
Bioavailability: Similar blood DHA from algal-oil capsules and cooked salmon (32 adults) and non-inferior to fish oil (74 adults).

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Isolated compounds versus whole extracts

Algal oil is an extracted oil, not the whole alga, so it supplies DHA (and some EPA) but not the other nutrients of seafood. NCCIH says for some conditions evidence for seafood is stronger than for supplements, and other nutrients in seafood may play a role.

Nutritional composition

Food sources of EPA and DHA named by NCCIH are cold-water fish such as salmon, mackerel and tuna, shellfish and fish oil supplements; ALA comes from flaxseed, soybean and canola oils, chia seeds and walnuts. Amounts per typical portion were not read from USDA or NIH ODS for this profile (ODS was blocked). In the 2008 trial, the DHA from algal-oil capsules was compared with DHA from assayed portions of cooked salmon.

10benefits and uses looked at

21studies and sources checked

High certaintybest evidence rating found

5lab markers tracked in trials

1 high certainty2 moderate certainty2 mixed findings2 low certainty3 not enough evidence

What was looked at

The 10 benefits and uses checked for Algal (algae) oil, each with how strong the evidence is. Tap one to open it.

A fish-free source of DHA (and sometimes EPA)High certainty
Raising DHA in the bloodModerate certainty
DHA status in vegetarians and vegansModerate certainty
Blood triglycerides and cholesterolMixed findings
Pregnancy and breastfeedingLow certainty
Memory and thinking in older adults with mild memory declineLow certainty
Children's reading and behaviourMixed findings
Heart attacks, strokes and heart rhythmNot enough evidence
Cystic fibrosis in childrenNot enough evidence
Eye disease, depression and ADHD (omega-3 in general)Not enough evidence

Lab markers tracked in the studies

DHA in blood fats and red blood cellsOmega-3 indexTriglyceridesLDL cholesterolHDL cholesterol

What is Algal (algae) oil good for?

The main studied uses and how strong the human evidence is for each. Most results show blood levels, not health outcomes, and several come from omega-3 in general rather than algal oil alone.

A fish-free source of DHA (and sometimes EPA)High certaintyAlgal oil is an oil made from algae. NCCIH, a US government health centre, calls algal oils a vegetarian source of DHA and says some also contain EPA. It is a different thing from fish oil, cod liver oil or krill oil, and from flaxseed oil, which carries a different omega-3 called ALA. The label tells you what a product contains. Raising DHA in the bloodModerate certaintyIn small trials in healthy adults, algal oil raised DHA in the blood about as well as cooked salmon or fish oil. This shows the DHA gets into the body. It does not show a health benefit by itself. DHA status in vegetarians and vegansModerate certaintyPlant foods give ALA but little or no EPA and DHA. A 2026 systematic review found vegan diets go with lower blood EPA and DHA, and that algal DHA improved DHA status. One study of 165 vegans found their omega-3 index was not lower than that of meat-eaters, so the gap is not the same in every group. In vegans with a low starting index, an algal supplement raised it. Blood triglycerides and cholesterolMixed findingsA review of 11 trials in 485 healthy people found algal DHA lowered triglycerides but also raised LDL ('bad') and HDL ('good') cholesterol. So the result is mixed: one change usually seen as helpful, one not. Pregnancy and breastfeedingLow certaintyIn breastfeeding women, algal oil DHA raised the DHA in breast milk. In pregnancy, a large Cochrane review of omega-3 in general (not algal oil alone) found fewer preterm births. Long-term benefits for children were mostly not found. Memory and thinking in older adults with mild memory declineLow certaintyOne 24-week trial of 485 older adults with mild, age-related memory decline found fewer errors on a learning test with DHA than with placebo, and better word recognition. Working memory and planning did not change. The source of the DHA is not named in the abstract, and the lead author works for an algal-DHA maker. Children's reading and behaviourMixed findingsTwo UK school trials gave children aged 7 to 9 algal DHA. The first found a benefit only in a subgroup with the lowest reading scores, plus fewer behaviour problems rated by parents. The repeat trial found no consistent difference. Heart attacks, strokes and heart rhythmNot enough evidenceNo trial of algal oil on heart attacks, strokes or deaths was found. Large reviews of omega-3 from mostly fish oil found little or no effect on deaths, heart events, stroke or arrhythmia, and a possible small fall in coronary events. Do not carry these results over to algal oil. Cystic fibrosis in childrenNot enough evidenceChildren with cystic fibrosis often have low DHA. In a one-year trial of 41 children, algal DHA improved a blood fat ratio but made no difference to lung flare-ups, lung function, growth or inflammation. Eye disease, depression and ADHD (omega-3 in general)Not enough evidenceNCCIH reports that omega-3 supplements did not slow age-related macular degeneration or beat placebo in a one-year dry-eye trial, that any effect on depression may be too small to matter, and that ADHD symptoms are not likely to improve. These are for omega-3 in general. No algal-oil-specific trial was found.

Benefits, one by one

Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.

A fish-free source of DHA (and sometimes EPA)

High certainty

Algal oil is an oil made from algae. NCCIH, a US government health centre, calls algal oils a vegetarian source of DHA and says some also contain EPA. It is a different thing from fish oil, cod liver oil or krill oil, and from flaxseed oil, which carries a different omega-3 called ALA. The label tells you what a product contains.

3 studiesCapsules, liquid oil and fortified foods. See the label for the DHA a…

Studies, doses and limits

What the trials found

NCCIH (updated November 2024) lists algal oils as a vegetarian source of DHA, some with EPA, next to fish oil, fish liver oil, krill oil and flaxseed oil. A 2007 trial in healthy adults found two different algal oils gave equivalent DHA and that a snack bar fortified with algal oil also delivered DHA. The NHS vegan-diet page lists ground linseed oil, rapeseed oil, chia seeds, hemp seeds and walnuts as vegan omega-3 sources and does not mention algal oil. Those foods supply ALA, not DHA or EPA.

Results

Algal oil is a real source of DHA. How much DHA and EPA a product holds differs by product, so the label matters. Amounts per portion for foods were not researched here.

Effect sizes as reported

No effect size applies: this is what the product contains.

Why this rating

High that DHA is present (NCCIH). This is not a trial of a health outcome.

Form and dose studied

Capsules, liquid oil and fortified foods. See the label for the DHA and EPA content.

Who was studied

General population, especially people who avoid fish.

Limits

The source types (strains) of algae in commercial products were not reviewed. Capsule shells and other ingredients vary by product.

Why researchers looked

People who do not eat fish look for another way to get the long-chain omega-3 fats EPA and DHA.

Traditional use

No traditional use is described in the sources read.

Proposed mechanism Established nutrition

Algae make DHA themselves. Algal oil carries that DHA in an oil that can be taken as a capsule or added to foods such as the fortified snack bar tested in one trial.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab. A fish allergy is not ruled out by the word 'algal'; no source read answered this.

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Raising DHA in the blood

Moderate certainty

In small trials in healthy adults, algal oil raised DHA in the blood about as well as cooked salmon or fish oil. This shows the DHA gets into the body. It does not show a health benefit by itself.

3 studiesAlgal-oil capsules and a fortified snack bar. Amounts studied are in …

Studies, doses and limits

What the trials found

Arterburn 2008: 32 healthy adults, 2 weeks, algal-oil capsules versus cooked salmon, each giving the same DHA. DHA rose about 80% in plasma phospholipids and about 25% in red blood cells in both groups; the authors called them bioequivalent. Arterburn 2007: two algal oils in capsules gave equivalent blood DHA, and the rise grew with the amount taken. Bailey 2025: 74 adults, algal oil versus fish oil, DHA and EPA in plasma phospholipids non-inferior to fish oil at 6 and 14 weeks.

Results

Three small trials agree that algal oil raises blood DHA, and the 2008 and 2025 trials found it similar to salmon and to fish oil. Two of the three are linked to makers of algal oil.

Effect sizes as reported

About +80% plasma phospholipid DHA and +25% red-cell DHA (2008); non-inferior to fish oil (2025, no numbers in the abstract).

Why this rating

Consistent across three randomised trials, but all small, short, measuring a blood marker, and two are industry-linked.

Form and dose studied

Algal-oil capsules and a fortified snack bar. Amounts studied are in the studies table.

Who was studied

Healthy adults.

Limits

A higher blood level is a marker, not a health benefit. The 2008 trial was open-label.

Why researchers looked

Before testing health effects, researchers checked whether algal DHA is absorbed as well as DHA from fish.

Proposed mechanism Human measurement

DHA from the oil is built into blood fats and red blood cell membranes; the trials measured this.

A proposed mechanism does not show that the effect happens in people.

Tolerated well in these trials (authors' words).

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DHA status in vegetarians and vegans

Moderate certainty

Plant foods give ALA but little or no EPA and DHA. A 2026 systematic review found vegan diets go with lower blood EPA and DHA, and that algal DHA improved DHA status. One study of 165 vegans found their omega-3 index was not lower than that of meat-eaters, so the gap is not the same in every group. In vegans with a low starting index, an algal supplement raised it.

3 studiesAlgal-derived omega-3 supplement (Sarter 2015). See studies table.

Studies, doses and limits

What the trials found

Chamorro 2026: 45 studies; vegetarian diets lowered blood EPA and DHA, particularly vegan diets; DHA from microalgae oil effectively improved serum DHA status, particularly in pregnancy and lactation. Sarter 2015: 165 long-term vegans had an average omega-3 index of 3.7%, similar to a cohort of omnivores from another study; in 46 vegans starting below 4%, a vegetarian omega-3 supplement made from algae raised the index from 3.1% to 4.8%.

Results

Algal DHA raises DHA status in people who avoid fish. Whether this improves health was not shown in these studies.

Effect sizes as reported

Omega-3 index 3.1% to 4.8% after 4 months (p = 0.009), in 46 vegans, no control group.

Why this rating

Moderate that algal DHA raises blood DHA in vegetarians and vegans. The status gap itself is mixed, and no health outcome was measured.

Form and dose studied

Algal-derived omega-3 supplement (Sarter 2015). See studies table.

Who was studied

Vegetarians and vegans, including pregnancy and breastfeeding in the review.

Limits

The 2015 supplement study had no comparison group. The review mixes many study designs and relies on diet reports.

Why researchers looked

Vegetarians and vegans do not eat fish, the usual source of EPA and DHA.

Proposed mechanism Hypothesis

Without fish, EPA and DHA must come from other sources or be made from ALA, which the body does only to a small extent (not tested in these studies).

A proposed mechanism does not show that the effect happens in people.

Pregnant or breastfeeding readers should ask a doctor or midwife.

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Blood triglycerides and cholesterol

Mixed findings

A review of 11 trials in 485 healthy people found algal DHA lowered triglycerides but also raised LDL ('bad') and HDL ('good') cholesterol. So the result is mixed: one change usually seen as helpful, one not.

3 studiesAlgal oil DHA at amounts well above typical label amounts in the tria…

Studies, doses and limits

What the trials found

Bernstein 2012 pooled 11 randomised trials with 485 healthy people; the middle amount of algal DHA was 1.68 g a day. Triglycerides fell by 0.20 mmol/L (CI -0.27 to -0.14), LDL cholesterol rose by 0.23 mmol/L (0.16 to 0.30) and HDL cholesterol rose by 0.07 mmol/L (0.05 to 0.10). NCCIH says a 2020 review of 23 omega-3 studies found EPA and DHA lower triglycerides by about 15%, and that prescription omega-3 products for very high triglycerides are a different product from supplements. The Cochrane 2020 review of omega-3 (mostly fish oil) also found about 15% lower triglycerides.

Results

Triglycerides go down, LDL goes up. The authors state that algal DHA may do both. Whether the net effect helps the heart was not tested.

Effect sizes as reported

Triglycerides -0.20 mmol/L; LDL +0.23 mmol/L; HDL +0.07 mmol/L.

Why this rating

The trials agree on direction but the LDL rise cuts against the triglyceride fall, healthy people only, and no heart outcomes.

Form and dose studied

Algal oil DHA at amounts well above typical label amounts in the trials pooled (middle 1.68 g a day).

Who was studied

Healthy people without heart disease.

Limits

Blood fats only. The effect in people with high triglycerides or heart disease is not covered.

Why researchers looked

Fish-oil omega-3 lowers triglycerides, so researchers asked whether algal DHA does the same.

Proposed mechanism Unknown

Not described in the meta-analysis.

A proposed mechanism does not show that the effect happens in people.

The LDL rise matters for anyone watching cholesterol. Ask a doctor or pharmacist.

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Pregnancy and breastfeeding

Low certainty

In breastfeeding women, algal oil DHA raised the DHA in breast milk. In pregnancy, a large Cochrane review of omega-3 in general (not algal oil alone) found fewer preterm births. Long-term benefits for children were mostly not found.

5 studiesSee the studies table for amounts used.

Studies, doses and limits

What the trials found

Yang 2022: 160 breastfeeding women in China, DHA from algal oil for 8 weeks; breast milk DHA 10.07 mg/100 mL versus 7.57 mg/100 mL in the control group. Middleton 2018 (Cochrane): 70 trials in 19,927 women using many omega-3 sources; preterm birth before 37 weeks 13.4% versus 11.9% and before 34 weeks 4.6% versus 2.7% (high-quality evidence); more pregnancies past 42 weeks (1.6% versus 2.6%). Carlson 2013 (KUDOS, 350 women, DHA capsules, source not named in the abstract): slightly longer pregnancy and bigger babies, fewer births before 34 weeks. Colombo 2019: no consistent long-term benefit for the children to age 6. NCCIH notes its own summary of pregnancy reviews is for omega-3 in general.

Results

Raising milk DHA is shown for algal oil. Preterm birth results are shown for omega-3 in general, not algal oil on its own. Children's later thinking and behaviour were mostly unchanged.

Effect sizes as reported

Breast milk DHA +2.5 mg/100 mL; preterm birth RR 0.89, early preterm RR 0.58 (all omega-3 sources).

Why this rating

Algal-specific evidence is one small breast-milk trial; the strong pregnancy evidence is for omega-3 in general, and long-term child results were mostly null.

Form and dose studied

See the studies table for amounts used.

Who was studied

Pregnant and breastfeeding women.

Limits

Milk DHA is a marker, not infant health. The pregnancy review mixes oil types.

Why researchers looked

DHA is a building block of the baby's brain and eyes, and vegetarians may have less of it.

Proposed mechanism Human measurement

Maternal DHA passes into breast milk and to the baby (the trials measured the levels).

A proposed mechanism does not show that the effect happens in people.

Ask a doctor or midwife before starting any supplement in pregnancy or breastfeeding.

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Memory and thinking in older adults with mild memory decline

Low certainty

One 24-week trial of 485 older adults with mild, age-related memory decline found fewer errors on a learning test with DHA than with placebo, and better word recognition. Working memory and planning did not change. The source of the DHA is not named in the abstract, and the lead author works for an algal-DHA maker.

2 studiesDHA by mouth (see studies table).

Studies, doses and limits

What the trials found

Yurko-Mauro 2010 (MIDAS): 485 healthy people aged 55 and over with a memory score at least one standard deviation below younger adults; DHA versus placebo for 24 weeks. Fewer six-pattern errors on the paired learning test (difference -1.63, 95% CI -3.1 to -0.14, p = 0.03) and better immediate and delayed verbal recognition memory. No change in working memory or executive function. Blood DHA doubled. No treatment-related serious adverse events. NCCIH says a 2022 review of 33 studies suggested omega-3 may protect against decline in healthy people, with no effect in people already diagnosed with Alzheimer's disease.

Results

A small, modest benefit on one test in one industry-linked trial.

Effect sizes as reported

PAL six-pattern errors -1.63 (95% CI -3.1 to -0.14).

Why this rating

One trial, one primary test, modest effect, industry-linked, DHA source not named.

Form and dose studied

DHA by mouth (see studies table).

Who was studied

Older adults with mild memory decline; not people with dementia.

Limits

Not repeated in the sources read. Does not show it prevents dementia.

Why researchers looked

Low blood DHA has been linked to memory decline in older people.

Proposed mechanism Author hypothesis

DHA plays a part in nerve cell function (the authors' background statement); not tested here.

A proposed mechanism does not show that the effect happens in people.

No treatment-related serious adverse events reported.

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Children's reading and behaviour

Mixed findings

Two UK school trials gave children aged 7 to 9 algal DHA. The first found a benefit only in a subgroup with the lowest reading scores, plus fewer behaviour problems rated by parents. The repeat trial found no consistent difference.

3 studiesAlgal oil DHA in both trials.

Studies, doses and limits

What the trials found

DOLAB 1 (Richardson 2012): 362 children, algal-oil DHA versus corn/soy oil; no effect on reading in the whole group; effect on reading in the 224 children with the lowest scores; parent-rated behaviour problems lower; little or no effect on teacher ratings or working memory. DOLAB 2 (Montgomery 2018): 376 children, same design, 16 weeks; no consistent differences. Both were funded by the supplier. NCCIH says omega-3 supplements for ADHD in children had conflicting results and a 2023 review of 36 studies did not find that symptoms are likely to improve.

Results

The first result did not hold up when repeated.

Effect sizes as reported

No consistent differences in DOLAB 2.

Why this rating

The first trial was positive only in a subgroup and the replication was null; both industry-funded.

Form and dose studied

Algal oil DHA in both trials.

Who was studied

Healthy UK children aged 7 to 9 reading below average.

Limits

Not people with ADHD. Short.

Why researchers looked

Omega-3 fats are linked to brain development and behaviour.

Proposed mechanism Unknown

Not tested.

A proposed mechanism does not show that the effect happens in people.

Children should only be given supplements on advice from a doctor or pharmacist.

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Heart attacks, strokes and heart rhythm

Not enough evidence

No trial of algal oil on heart attacks, strokes or deaths was found. Large reviews of omega-3 from mostly fish oil found little or no effect on deaths, heart events, stroke or arrhythmia, and a possible small fall in coronary events. Do not carry these results over to algal oil.

2 studiesNot applicable.

Studies, doses and limits

What the trials found

Abdelhamid 2020 (Cochrane): 86 trials, 162,796 adults; all-cause death RR 0.97 (0.93 to 1.01); cardiovascular events RR 0.96 (0.92 to 1.01); stroke RR 1.02 (0.94 to 1.12); arrhythmia RR 0.99 (0.92 to 1.06); coronary heart disease events RR 0.91 (0.85 to 0.97), low-certainty. Most trials used capsules of fish oil. NCCIH reports similar mixed findings.

Results

Nothing algal-specific. Fish-oil trials show little or no effect on most heart outcomes.

Effect sizes as reported

See evidence text.

Why this rating

No algal-oil outcome trial was found; the large reviews are of other omega-3 sources.

Who was studied

Adults at varying heart risk in the Cochrane review.

Limits

Not algal oil.

Why researchers looked

Fish-oil omega-3 has been studied widely for heart protection.

Proposed mechanism Unknown

Not tested for algal oil.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab for atrial fibrillation.

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Cystic fibrosis in children

Not enough evidence

Children with cystic fibrosis often have low DHA. In a one-year trial of 41 children, algal DHA improved a blood fat ratio but made no difference to lung flare-ups, lung function, growth or inflammation.

1 studiesHigh amounts (see studies table).

Studies, doses and limits

What the trials found

Alicandro 2013: 41 children aged 6 to 12, algal DHA versus germ oil for 12 months. The arachidonic acid to DHA ratio fell 73% versus 10% at 6 months. No differences in the number of pulmonary exacerbations, lung function, body mass index, body composition or inflammation markers.

Results

A blood marker changed; no clinical benefit was seen.

Effect sizes as reported

AA:DHA ratio -73% versus -10% (P = 0.001).

Why this rating

One small trial with no clinical benefit.

Form and dose studied

High amounts (see studies table).

Who was studied

Children with cystic fibrosis.

Limits

Rare condition, small trial.

Why researchers looked

Children with cystic fibrosis have low blood DHA.

Proposed mechanism Unknown

Not tested.

A proposed mechanism does not show that the effect happens in people.

Use only under a specialist's care.

Eye disease, depression and ADHD (omega-3 in general)

Not enough evidence

NCCIH reports that omega-3 supplements did not slow age-related macular degeneration or beat placebo in a one-year dry-eye trial, that any effect on depression may be too small to matter, and that ADHD symptoms are not likely to improve. These are for omega-3 in general. No algal-oil-specific trial was found.

1 studiesNot applicable.

Studies, doses and limits

What the trials found

NCCIH (November 2024): AREDS2 (over 4,000 people) found adding EPA and DHA gave no extra benefit for macular degeneration; the DREAM trial (535 people with dry eye) found omega-3 no better than placebo; a 2021 review of 35 depression studies (1,964 people) found an effect, if any, may be too small to be meaningful, with low or very low quality evidence; a 2023 review of 36 studies found no evidence ADHD symptoms are likely to improve.

Results

No benefit shown for these uses.

Why this rating

Evidence is for omega-3 in general and is mostly negative or low quality.

Who was studied

Mixed adult and child groups.

Limits

Taken from NCCIH's summary; individual reviews were not re-read.

Why researchers looked

Omega-3 fats are in the retina and brain.

Proposed mechanism Unknown

Not tested.

A proposed mechanism does not show that the effect happens in people.

Do not stop prescribed treatment on your own.

¹⁹

Connections to the rest of health

How Algal (algae) oil connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.

Explore every connection: goals, body systems, organs, symptoms, genes

Kind of connection Connected to Search

A. Wellness goals

Connected to	Evidence status	Context	Studies
Balanced Nutrition	High certainty	A fish-free source of DHA (and sometimes EPA): Algal oil is an oil made from algae. NCCIH, a US government health centre, calls algal oils a vegetarian source of DHA and says some also contain EPA. It is a different thing from fish oil, cod liver oil or krill oil, and from flaxseed oil, which carries a different omega-3 called ALA. The label tells you what a product contains.	^{19 20 4}
Brain Health	High certainty	A fish-free source of DHA (and sometimes EPA): Algal oil is an oil made from algae. NCCIH, a US government health centre, calls algal oils a vegetarian source of DHA and says some also contain EPA. It is a different thing from fish oil, cod liver oil or krill oil, and from flaxseed oil, which carries a different omega-3 called ALA. The label tells you what a product contains.	^{19 20 4}
Balanced Nutrition	Moderate certainty	Raising DHA in the blood: In small trials in healthy adults, algal oil raised DHA in the blood about as well as cooked salmon or fish oil. This shows the DHA gets into the body. It does not show a health benefit by itself. DHA status in vegetarians and vegans: Plant foods give ALA but little or no EPA and DHA. A 2026 systematic review found vegan diets go with lower blood EPA and DHA, and that algal DHA improved DHA status. One study of 165 vegans found their omega-3 index was not lower than that of meat-eaters, so the gap is not the same in every group. In vegans with a low starting index, an algal supplement raised it.	^{5 4 6 9 16 20}
Heart Health	Moderate certainty	Raising DHA in the blood: In small trials in healthy adults, algal oil raised DHA in the blood about as well as cooked salmon or fish oil. This shows the DHA gets into the body. It does not show a health benefit by itself.	^{5 4 6}
Cholesterol Balance	Mixed findings	Blood triglycerides and cholesterol: A review of 11 trials in 485 healthy people found algal DHA lowered triglycerides but also raised LDL ('bad') and HDL ('good') cholesterol. So the result is mixed: one change usually seen as helpful, one not.	^{7 19 1}
Heart Health	Mixed findings	Blood triglycerides and cholesterol: A review of 11 trials in 485 healthy people found algal DHA lowered triglycerides but also raised LDL ('bad') and HDL ('good') cholesterol. So the result is mixed: one change usually seen as helpful, one not.	^{7 19 1}
Womens Wellness	Low certainty	Pregnancy and breastfeeding: In breastfeeding women, algal oil DHA raised the DHA in breast milk. In pregnancy, a large Cochrane review of omega-3 in general (not algal oil alone) found fewer preterm births. Long-term benefits for children were mostly not found.	^{17 13 8 10 19}
Balanced Nutrition	Low certainty	Pregnancy and breastfeeding: In breastfeeding women, algal oil DHA raised the DHA in breast milk. In pregnancy, a large Cochrane review of omega-3 in general (not algal oil alone) found fewer preterm births. Long-term benefits for children were mostly not found.	^{17 13 8 10 19}
Memory Support	Low certainty	Memory and thinking in older adults with mild memory decline: One 24-week trial of 485 older adults with mild, age-related memory decline found fewer errors on a learning test with DHA than with placebo, and better word recognition. Working memory and planning did not change. The source of the DHA is not named in the abstract, and the lead author works for an algal-DHA maker.	^{18 19}
Brain Health	Low certainty	Memory and thinking in older adults with mild memory decline: One 24-week trial of 485 older adults with mild, age-related memory decline found fewer errors on a learning test with DHA than with placebo, and better word recognition. Working memory and planning did not change. The source of the DHA is not named in the abstract, and the lead author works for an algal-DHA maker.	^{18 19}
Healthy Aging	Low certainty	Memory and thinking in older adults with mild memory decline: One 24-week trial of 485 older adults with mild, age-related memory decline found fewer errors on a learning test with DHA than with placebo, and better word recognition. Working memory and planning did not change. The source of the DHA is not named in the abstract, and the lead author works for an algal-DHA maker.	^{18 19}
Cognitive Performance	Mixed findings	Children's reading and behaviour: Two UK school trials gave children aged 7 to 9 algal DHA. The first found a benefit only in a subgroup with the lowest reading scores, plus fewer behaviour problems rated by parents. The repeat trial found no consistent difference.	^{15 14 19}
Better Focus	Mixed findings	Children's reading and behaviour: Two UK school trials gave children aged 7 to 9 algal DHA. The first found a benefit only in a subgroup with the lowest reading scores, plus fewer behaviour problems rated by parents. The repeat trial found no consistent difference.	^{15 14 19}
Heart Health	Not enough evidence	Heart attacks, strokes and heart rhythm: No trial of algal oil on heart attacks, strokes or deaths was found. Large reviews of omega-3 from mostly fish oil found little or no effect on deaths, heart events, stroke or arrhythmia, and a possible small fall in coronary events. Do not carry these results over to algal oil.	^{1 19}
Lung Support	Not enough evidence	Cystic fibrosis in children: Children with cystic fibrosis often have low DHA. In a one-year trial of 41 children, algal DHA improved a blood fat ratio but made no difference to lung flare-ups, lung function, growth or inflammation.	³
Mood Balance	Not enough evidence	Eye disease, depression and ADHD (omega-3 in general): NCCIH reports that omega-3 supplements did not slow age-related macular degeneration or beat placebo in a one-year dry-eye trial, that any effect on depression may be too small to matter, and that ADHD symptoms are not likely to improve. These are for omega-3 in general. No algal-oil-specific trial was found.	¹⁹
Brain Health	Not enough evidence	Eye disease, depression and ADHD (omega-3 in general): NCCIH reports that omega-3 supplements did not slow age-related macular degeneration or beat placebo in a one-year dry-eye trial, that any effect on depression may be too small to matter, and that ADHD symptoms are not likely to improve. These are for omega-3 in general. No algal-oil-specific trial was found.	¹⁹

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Whole Body	Biological association	High certainty	Studied for: A fish-free source of DHA (and sometimes EPA) Studied for: Raising DHA in the blood	^{19 20 4 5 6 9 16}
Nutrition	Biological association	High certainty	Studied for: A fish-free source of DHA (and sometimes EPA) Studied for: DHA status in vegetarians and vegans	^{19 20 4 9 16 17 13 8 10}
Cardiovascular System	Biological association	Moderate certainty	Studied for: Raising DHA in the blood Studied for: Blood triglycerides and cholesterol	^{5 4 6 7 19 1}
Heart Circulation	Biological association	Mixed findings	Studied for: Blood triglycerides and cholesterol Studied for: Heart attacks, strokes and heart rhythm	^{7 19 1}
Reproductive System	Biological association	Low certainty	Studied for: Pregnancy and breastfeeding	^{17 13 8 10 19}
Nervous System	Biological association	Low certainty	Studied for: Memory and thinking in older adults with mild memory decline Studied for: Children's reading and behaviour	^{18 19 15 14}
Brain Focus	Biological association	Low certainty	Studied for: Memory and thinking in older adults with mild memory decline Studied for: Children's reading and behaviour	^{18 19 15 14}
Respiratory System	Biological association	Not enough evidence	Studied for: Cystic fibrosis in children	³
Stress Mood	Biological association	Not enough evidence	Studied for: Eye disease, depression and ADHD (omega-3 in general)	¹⁹

E. Health conditions

Connected to	Kind of connection	Evidence status	Context	Studies
Atrial fibrillation	Adverse effect or risk	Meta analysis	More atrial fibrillation only in high-risk people taking high amounts of omega-3 (algal oil not analysed alone). More atrial fibrillation with high amounts of omega-3 in high-risk people (algal oil not analysed alone). Preparation or compound: EPA plus DHA	²
Prolonged bleeding time		Meta analysis	No overall rise in bleeding; modest rise with high-dose purified EPA. Preparation or compound: Omega-3	¹²

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
LDL cholesterol	Adverse effect or risk	Meta analysis	Raised LDL cholesterol in healthy people in 11 trials. Preparation or compound: Algal oil DHA	⁷
Triglycerides		Meta analysis	Lower triglycerides but higher LDL cholesterol in healthy people. Preparation or compound: Algal oil DHA	⁷
DHA in blood fats and red blood cells	Biological association	Moderate certainty	Measured in trials: higher. A lab change is not the same as a health benefit.	^{5 6 4}
Omega-3 index	Biological association	Low certainty	Measured in trials: higher. A lab change is not the same as a health benefit.	¹⁶
Triglycerides	Biological association	Moderate certainty	Measured in trials: lower. A lab change is not the same as a health benefit.	⁷
LDL cholesterol	Biological association	Moderate certainty	Measured in trials: higher (unfavourable). A lab change is not the same as a health benefit.	⁷
HDL cholesterol	Biological association	Low certainty	Measured in trials: higher (small). A lab change is not the same as a health benefit.	⁷

K. Biological pathways

Connected to	Kind of connection	Evidence status	Context	Studies
DHA	Preliminary mechanism	Human	Main fat in algal oil.	^{19 5}

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
DHA (docosahexaenoic acid)	Biological association	Human	The main fat in algal oil. Algal-oil DHA raised blood DHA similar to salmon or fish oil in small trials. Preparation or compound: Algal oil	^{19 5 6}
EPA (eicosapentaenoic acid)	Biological association	Human	Raised in blood along with DHA in the 2025 trial of microalgal oil. Preparation or compound: Some algal oils	^{19 6}

Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).

Evidence at a glance: what the research found for 10 outcomes

1High certainty

2Moderate certainty

2Low certainty

2Mixed findings

3Not enough evidence

Each outcome below is one thing researchers measured. Certainty is how far the evidence can be trusted, not how well it works. The full studies are on the next tab.

A fish-free source of DHA (and sometimes EPA) 3 studies High certainty Raising DHA in the blood 3 studies Moderate certainty DHA status in vegetarians and vegans 3 studies Moderate certainty Blood triglycerides and cholesterol 3 studies Mixed findings Pregnancy and breastfeeding 5 studies Low certainty Memory and thinking in older adults with mild memory decline 2 studies Low certainty Children's reading and behaviour 3 studies Mixed findings Heart attacks, strokes and heart rhythm 2 studies Not enough evidence Cystic fibrosis in children 1 study Not enough evidence Eye disease, depression and ADHD (omega-3 in general) 1 study Not enough evidence

The evidence

The research centre for Algal (algae) oil. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).

How we rate evidence

High certainty

Several well-run trials or reviews agree; further research is unlikely to change the picture much.

Moderate certainty

Good trials point the same way, but some doubt remains.

Low certainty

Small, short or inconsistent trials. The finding could change with better research.

Very low certainty

Very little or very weak human data. Treat as a possibility only.

Mixed findings

Trials or reviews disagree with each other.

Not enough evidence

Not enough human research to say either way.

Evidence against

Good research found no benefit, or found harm.

We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We read the NCCIH omega-3 page and the NHS vegan-diet page in full, and re-read PubMed abstracts for trials, reviews and meta-analyses. Only abstracts were read for studies. The NIH Office of Dietary Supplements fact sheet was blocked and is marked unread.

Study library: every study we checked 21

Design Research type Year from Search

Study	Design	People	Product, dose, length	Result
Abdelhamid 2020 Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev · PMID 32114706 · DOI	Systematic review	162796 86 randomised trials, 162,796 adults (12 to 88 months)	Long-chain omega-3 (EPA and DHA) from mostly fish-oil capsules, plus foods and advice; ALA separately Mostly fish oil capsules (not algal oil) 0.5 g to more than 5 g a day 12 to 88 months · vs Usual or lower intake	Little or no effect on all-cause death, cardiovascular events, stroke or arrhythmia. A possible small fall in coronary heart disease deaths and events (low-certainty evidence). Triglycerides fell by about 15% (high-certainty evidence). All-cause death RR 0.97; cardiovascular events RR 0.96; coronary events RR 0.91; triglycerides about -15% (0.93 to 1.01; 0.92 to 1.01; 0.85 to 0.97) Methods, limits and funding Outcomes: Death, heart events, stroke, arrhythmia, triglycerides Limitations: Algal oil was not analysed on its own; most trials used fish oil. Funding and conflicts: Not stated in the abstract. Read: abstract
Abuknesha 2026 Effects of Omega-3 Fatty Acid Treatment on Risk for Atrial Fibrillation: An Updated Meta-Analysis of 35 Trials including 114 592 Individuals. Circ Arrhythm Electrophysiol · PMID 42517224 · DOI	Meta-analysis	114592 35 randomised trials (37 data sets), 114,592 people aged 50 or over	EPA plus DHA (not algal oil specifically) EPA plus DHA supplements At least 500 mg a day; split above and below 1,500 mg a day 12 months or longer · vs Control group	Only people at high heart-disease risk taking more than 1,500 mg a day of EPA plus DHA had significantly more atrial fibrillation (odds ratio 1.43, absolute difference 0.8%). The other three groups (high risk with lower amounts, low risk with lower or higher amounts) showed no significant rise. High risk, high amount: OR 1.43; others OR 1.03 to 1.07 (1.14 to 1.79 for the high-risk, high-amount group) Methods, limits and funding Outcomes: New atrial fibrillation Limitations: Algal oil was not analysed on its own. Trials of older people for 12 months or more. Funding and conflicts: Authors disclose ties to the omega-3 industry: one is chief medical officer of a company that sells omega-3 products; one received a GOED research award; one holds stock in a fatty-acid testing lab (conflict statement). Read: abstract
Alicandro 2013 A randomized placebo-controlled study on high-dose oral algal docosahexaenoic acid supplementation in children with cystic fibrosis. Prostaglandins Leukot Essent Fatty Acids · PMID 23266209 · DOI	Randomised controlled trial	41 41 children aged 6 to 12 with cystic fibrosis	Algal DHA Algal DHA oil 100 mg per kg a day for the first month, then 1 g a day 12 months · vs Germ oil placebo	The arachidonic acid to DHA ratio fell more with DHA (-73% versus -10% at 6 months). No differences in any other outcome. The authors concluded DHA for one year did not give a significant biochemical or clinical improvement. AA:DHA ratio -73% versus -10% (P = 0.001); no difference in clinical outcomes (Not given in the abstract) Methods, limits and funding Outcomes: Ratio of arachidonic acid to DHA in plasma; lung flare-ups, lung function, growth, inflammation markers Limitations: Only 41 children, a rare condition, very high amounts. Funding and conflicts: Not stated in the abstract. Read: abstract
Arterburn 2007 Bioequivalence of Docosahexaenoic acid from different algal oils in capsules and in a DHA-fortified food. Lipids · PMID 17713804 · DOI	Randomised controlled trial	Healthy adults; 12 per group across capsule groups at three amounts, plus a fortified-food group	Two algal DHA oils (called DHASCO-T and DHASCO-S) in capsules, and a snack bar fortified with algal DHA oil Algal oil capsules; algal-oil-fortified snack bar 200, 600 and 1,000 mg DHA a day 28 days · vs Placebo	Both algal oils gave equivalent DHA levels. The rise in blood DHA grew in a straight line with the amount taken. The fortified snack bar gave equivalent DHA. The authors reported an excellent safety and tolerability profile. Plasma phospholipid DHA rose by 1.17, 2.28 and 3.03 g per 100 g fatty acid at the three amounts (Not given in the abstract) Methods, limits and funding Outcomes: DHA in plasma phospholipids and red blood cells; safety Limitations: Small groups of 12, 28 days only, healthy adults. Blood levels only. Funding and conflicts: Not stated in the abstract. The first author is affiliated with Martek Biosciences, a maker of algal DHA oil. Treat as industry-linked. Read: abstract
Arterburn 2008 Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid. J Am Diet Assoc · PMID 18589030 · DOI	Randomised controlled trial	32 32 healthy men and women aged 20 to 65	Algal-oil capsules versus cooked salmon portions, each giving DHA Algal-oil capsules (DHA) 600 mg DHA a day 2 weeks · vs Cooked salmon (open-label, parallel groups)	DHA rose by about 80% in plasma phospholipids and about 25% in red blood cells in both groups. Changes were similar between groups, and the authors called the two sources bioequivalent for delivering DHA. Both were generally well tolerated. About +80% plasma phospholipid DHA and +25% red-cell DHA in both groups (Not given in the abstract) Methods, limits and funding Outcomes: Change in DHA in plasma phospholipids and red blood cells Limitations: Small, short, open-label (not blinded). It measured blood levels of DHA, not health outcomes. Funding and conflicts: Not stated in the abstract. The first author's affiliation in the abstract is a company, Alba Therapeutics; treat as possibly industry-linked. Read: abstract
Bailey 2025 Comparative Bioavailability of DHA and EPA from Microalgal and Fish Oil in Adults. Int J Mol Sci · PMID 41096614 · DOI	Randomised controlled trial	74 74 adult men and women	Omega-3 supplements made from microalgal oil versus fish oil Microalgal oil and fish oil supplements Not given in the abstract 6 and 14 weeks · vs Fish oil supplement (double-blind, placebo-controlled, parallel groups)	DHA and EPA bioavailability from microalgal oil was statistically non-inferior to fish oil, despite differences in production and make-up. Non-inferior (no numbers given in the abstract) (Not given in the abstract) Methods, limits and funding Outcomes: DHA and EPA in plasma phospholipids Limitations: Blood levels only. Small. Numbers not in the abstract. Funding and conflicts: Industry-linked: five authors work for dsm-firmenich, and the statistician was contracted by dsm-firmenich (abstract conflict statement). Read: abstract
Bernstein 2012 A meta-analysis shows that docosahexaenoic acid from algal oil reduces serum triglycerides and increases HDL-cholesterol and LDL-cholesterol in persons without coronary heart disease. J Nutr · PMID 22113870 · DOI	Meta-analysis	485 11 randomised trials in 485 healthy people (published 1996 to 2011)	Algal oil DHA Algal oil Median 1.68 g DHA a day across trials Varied · vs Control (placebo or other)	Triglycerides fell, LDL cholesterol rose and HDL cholesterol rose. Triglycerides -0.20 mmol/L; LDL cholesterol +0.23 mmol/L; HDL cholesterol +0.07 mmol/L (TG -0.27 to -0.14; LDL 0.16 to 0.30; HDL 0.05 to 0.10) Methods, limits and funding Outcomes: Triglycerides, LDL cholesterol, HDL cholesterol Limitations: Healthy people, not people with heart disease. Typical trial amounts were large. Blood fats only, not heart attacks or strokes. Funding and conflicts: Not stated in the abstract. Read: abstract
Carlson 2013 DHA supplementation and pregnancy outcomes. Am J Clin Nutr · PMID 23426033 · DOI	Randomised controlled trial	350 350 pregnant women in the United States (the KUDOS trial)	DHA capsules (the abstract does not name the source of the DHA) DHA capsules 600 mg DHA a day offered; average taken 469 mg a day From before 20 weeks of pregnancy to birth · vs Placebo capsules	DHA raised mother and cord-blood DHA, gave a slightly longer pregnancy (2.9 days), and bigger babies (172 g heavier). Fewer babies were born before 34 weeks. No safety concerns were found. Gestation +2.9 days (p = 0.041); birth weight +172 g (p = 0.004); births before 34 weeks fewer (p = 0.025) (Not given in the abstract) Methods, limits and funding Outcomes: Mother and baby DHA status, length of pregnancy, birth size, safety Limitations: The abstract does not say whether the DHA came from algae, so it is evidence for DHA in general, not proven for algal oil. The number of early births was small. Funding and conflicts: Not stated in the abstract. Read: abstract
Chamorro 2026 Vegetarian Diets and Their Effect on n-3 Polyunsaturated Fatty Acids Status in Humans: Systematic Review. Lipids · PMID 40958088 · DOI	Systematic review	45 45 studies of vegetarian and vegan diets, searched to 2023	Vegetarian and vegan diets; DHA from microalgae oil as a supplement Diet pattern; microalgae oil Varied · vs Omnivore diets	Vegetarian diets raised intake of linoleic acid and ALA but lowered blood EPA and DHA, especially in vegans. DHA from microalgae oil effectively improved DHA status, particularly in pregnancy and lactation. Not given in the abstract (Not given in the abstract) Methods, limits and funding Outcomes: Blood levels of EPA and DHA Limitations: The authors name varied study designs, possible bias in dietary reporting, and inconsistent measurement. Blood status, not health outcomes. Funding and conflicts: Not stated in the abstract. Read: abstract
Colombo 2019 The Kansas University DHA Outcomes Study (KUDOS) clinical trial: long-term behavioral follow-up of the effects of prenatal DHA supplementation. Am J Clin Nutr · PMID 31004139 · DOI	Randomised controlled trial	301 About 200 children of 301 mothers followed from 10 months to 6 years	Prenatal DHA (the abstract does not name the source) DHA capsules 600 mg DHA a day to the mother From 14.5 weeks of pregnancy to delivery · vs Placebo	Few positive long-term effects. Higher maternal blood DHA was linked to higher verbal and full-scale IQ at 5 and 6 years, but this disappeared after accounting for family social and economic status. No consistent long-term benefit into childhood. No consistent long-term benefit (Not given in the abstract) Methods, limits and funding Outcomes: Child thinking and behaviour tests from 10 months to 6 years Limitations: About a third of children were lost to follow-up. The source of the DHA is not named in the abstract. Funding and conflicts: Not stated in the abstract. Read: abstract
Fedorova-Dahms 2011 Safety evaluation of Algal Oil from Schizochytrium sp. Food Chem Toxicol · PMID 20933569 · DOI	Animal toxicity study rat	Sprague-Dawley rats (90-day feeding study) plus gene and chromosome tests	Algal oil from Schizochytrium sp. Algal oil 0.5, 1.5 and 5% of the diet (rats) 90 days · vs Basal diet and a diet with 5% menhaden fish oil	All gene-damage tests were negative. No treatment-related harm at any level tested. Higher liver weights and lung changes seen at the top level were also seen with the fish oil control and were not considered adverse. No observed adverse effect at the highest level fed (5% of the diet) (Not applicable) Methods, limits and funding Outcomes: Gene mutation and chromosome damage tests; body weight, blood tests, organs Limitations: Rats and test-tube tests only. It does not show safety in people. Funding and conflicts: Authors' affiliations include Martek Biosciences (author list), so treat as industry-linked. Funding not stated in the abstract. Read: abstract
Javaid 2024 Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Am Heart Assoc · PMID 38742535 · DOI	Meta-analysis	120643 11 randomised trials, 120,643 patients	Omega-3 PUFAs (not algal oil specifically) Omega-3 capsules Varied Varied · vs Control group	No overall difference in bleeding between omega-3 and control. High-dose purified EPA showed a 50% higher relative risk of bleeding, a modest 0.6% rise in absolute risk. Bleeding was linked to the EPA dose, not to background antiplatelet use. Rate ratio 1.09 overall; high-dose purified EPA relative risk about 1.5 (0.91 to 1.31 overall) Methods, limits and funding Outcomes: Bleeding events Limitations: Algal oil was not studied separately. The result for purified EPA may not apply to DHA-rich algal oil. Funding and conflicts: Not stated in the abstract. Read: abstract
Middleton 2018 Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev · PMID 30480773 · DOI	Systematic review	19927 70 randomised trials in 19,927 pregnant women	Omega-3 long-chain fats from supplements or food (many kinds of oil, not only algal) Mixed omega-3 sources Varied Varied · vs Placebo or no omega-3	Preterm birth before 37 weeks fell (13.4% versus 11.9%) and before 34 weeks fell (4.6% versus 2.7%), both rated high-quality evidence. Low birth weight fell. Pregnancies went past 42 weeks more often (1.6% to 2.6%). Very few differences were found in children's thinking, vision, language or behaviour. Preterm birth RR 0.89; early preterm birth RR 0.58; post-term RR 1.61 (0.81 to 0.97; 0.44 to 0.77; 1.11 to 2.33) Methods, limits and funding Outcomes: Preterm birth, birth weight, pregnancy length, maternal and child outcomes Limitations: Covers all omega-3 sources together, so it says little about algal oil specifically. Child outcomes were mostly low-quality evidence. Funding and conflicts: The reviewers declare funding and fees from public and food-industry sources unrelated to this review; some were investigators on included trials (conflict statement). Read: abstract
Montgomery 2018 Docosahexaenoic acid for reading, working memory and behavior in UK children aged 7-9: A randomized controlled trial for replication (the DOLAB II study). PLoS One · PMID 29462158 · DOI	Randomised controlled trial	376 376 healthy UK children aged 7 to 9 reading below the 20th centile	DHA from algal oil Algal oil 600 mg DHA a day 16 weeks · vs Corn and soybean oil placebo	No consistent differences between DHA and placebo. The trial did not repeat the earlier trial's positive findings. No consistent differences (Not given in the abstract) Methods, limits and funding Outcomes: Reading, working memory, behaviour Limitations: Null result; some behaviour subscales showed minor differences. Funding and conflicts: Industry-funded: DSM Nutritional Products funded the trial and supplied product and placebo (conflict statement). Registration: ISRCTN48803273 Read: abstract
Richardson 2012 Docosahexaenoic acid for reading, cognition and behavior in children aged 7-9 years: a randomized, controlled trial (the DOLAB Study). PLoS One · PMID 22970149 · DOI	Randomised controlled trial	362 362 healthy UK children aged 7 to 9 who were reading below average	DHA from algal oil Algal oil 600 mg DHA a day Not given in the abstract · vs Corn and soybean oil placebo	No effect on reading in the whole group. In a pre-planned subgroup of 224 children with the lowest reading scores there was an effect on reading, and parents rated fewer behaviour problems. Little or no effect on teacher ratings or working memory. No effect overall; subgroup effect only (Not given in the abstract) Methods, limits and funding Outcomes: Reading, working memory, parent- and teacher-rated behaviour Limitations: The main result was null, and the positive findings come from a subgroup. Funding and conflicts: Industry-funded: funding, product and placebo came from Martek Biosciences; one author is a paid consultant to omega-3 firms (conflict statement). Registration: NCT01066182 Read: abstract
Sarter 2015 Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr · PMID 24679552 · DOI	Uncontrolled before after	165 165 long-term vegans; 46 with an omega-3 index below 4% took the supplement	A vegetarian (algal-derived) omega-3 supplement Algal-derived DHA plus EPA supplement 254 mg DHA plus EPA a day 4 months	The vegan group's average omega-3 index was 3.7%, similar to a group of omnivores from another study. In the 46 who took the supplement it rose from 3.1% to 4.8%. Omega-3 index 3.1% to 4.8% (p = 0.009) (Not given in the abstract) Methods, limits and funding Outcomes: Omega-3 index (DHA plus EPA in red blood cells) Limitations: No comparison group, so the rise cannot be separated from other changes. Only people with low starting levels got the supplement. Funding and conflicts: Not stated in the abstract. One author is linked to OmegaQuant Analytics, a blood-testing lab (stated in the author list). Read: abstract
Yang 2022 Impact of DHA from Algal Oil on the Breast Milk DHA Levels of Lactating Women: A Randomized Controlled Trial in China. Nutrients · PMID 36014916 · DOI	Randomised controlled trial	160 160 healthy breastfeeding women in Nanjing, China (30 to 50 days after birth); 137 finished	DHA from algal oil Algal oil DHA 200 mg DHA a day 8 weeks · vs Control group (no supplement)	After 8 weeks, breast milk DHA was higher in the supplement group (10.07 mg/100 mL, 0.40%) than in the control group (7.57 mg/100 mL, 0.28%). The effect was weaker in women whose diet was mainly cereals, beans other than soy, potatoes and nuts. 10.07 versus 7.57 mg/100 mL (p = 0.012); 0.40% versus 0.28% (p = 0.001) (Not given in the abstract) Methods, limits and funding Outcomes: DHA in breast milk Limitations: Breast milk levels only, not infant health. Short. 23 women dropped out. Funding and conflicts: The abstract says the authors declare no competing interests and the funders had no role. Read: abstract
Yurko-Mauro 2010 Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline. Alzheimers Dement · PMID 20434961 · DOI	Randomised controlled trial	485 485 healthy people aged 55 or over with mild memory decline (MIDAS trial, 19 US sites)	DHA by mouth (the abstract does not name the source) DHA 900 mg DHA a day 24 weeks · vs Matching placebo	Fewer errors on the learning test with DHA than with placebo (difference -1.63, p = 0.03), and better verbal recognition memory. No difference in working memory or executive function. Blood DHA doubled. No treatment-related serious adverse events. PAL six-pattern errors -1.63 (-3.1 to -0.14) Methods, limits and funding Outcomes: Paired Associate Learning test errors; memory tests Limitations: A modest result on one main test. The abstract does not state the DHA source. One trial. Funding and conflicts: Industry-linked: the lead author is in the clinical research department of Martek Biosciences (affiliation in the abstract). Read: abstract
s-nccih-omega3 NCCIH: Omega-3 Supplements: What You Need To Know (last updated November 2024) · Source	Regulator page n/a			Methods, limits and funding Read: full-text
s-nhs-vegan NHS: The vegan diet (page last reviewed 5 June 2026) · Source	Regulator page n/a			Methods, limits and funding Read: full-text
s-ods-omega3 NIH Office of Dietary Supplements: Omega-3 Fatty Acids fact sheet (health professional version) · Source	Regulator page n/a			Methods, limits and funding Read: not-read

What we do not know yet

No trial of algal oil on heart attacks, strokes or death was found.
No source answers whether people with fish or shellfish allergy can use algal oil.
No study of algal oil products for oxidation, contaminants or label accuracy was found.
Pregnancy outcome evidence is for omega-3 in general; the pregnancy trials read do not name the DHA source.
The NIH Office of Dietary Supplements fact sheet could not be read (HTTP 403).
Amounts of DHA and EPA per portion of food were not researched.

How new research is added

New studies are found by a saved PubMed search and placed in a review queue before the page changes.

Lab markers

What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".

Metabolic 3

●

Triglycerides

Lower in trials

A type of fat in the blood; high levels are linked to heart disease risk.

Moderate certainty

Results and what it means

Why it was measured

Omega-3 fats from fish lower them.

Statistical vs. clinical meaning

Consistent fall in healthy people.

Safety implication

Comes with a rise in LDL cholesterol.

Study	Result	People	Product
⁷	-0.20 mmol/L (CI -0.27 to -0.14)	485 healthy people in 11 trials	Algal oil DHA, middle amount 1.68 g a day

⁷

●

LDL cholesterol

Higher (unfavourable) in trials

The cholesterol carried in low-density particles; high levels are linked to heart disease risk.

Moderate certainty

Results and what it means

Why it was measured

Checked as a safety measure alongside triglycerides.

Statistical vs. clinical meaning

A rise is usually seen as unfavourable.

Safety implication

Worth knowing for anyone who is watching their cholesterol.

Study	Result	People	Product
⁷	+0.23 mmol/L (CI 0.16 to 0.30)	485 healthy people in 11 trials	Algal oil DHA, middle amount 1.68 g a day

⁷

●

HDL cholesterol

Higher (small) in trials

The cholesterol carried in high-density particles, often called the 'good' type.

Low certainty

Results and what it means

Why it was measured

Checked alongside the other blood fats.

Statistical vs. clinical meaning

Small change; health meaning unclear.

Safety implication

None.

Study	Result	People	Product
⁷	+0.07 mmol/L (CI 0.05 to 0.10)	485 healthy people in 11 trials	Algal oil DHA

⁷

Other 2

●

DHA in blood fats and red blood cells

Higher in trials

How much DHA sits in blood plasma fats and red blood cell membranes.

Moderate certainty

Results and what it means

Why it was measured

It shows whether DHA from the oil is absorbed.

Statistical vs. clinical meaning

Shows absorption; not a health outcome.

Safety implication

None noted in the abstracts.

Study	Result	People	Product
⁵	Plasma phospholipid DHA about +80%, red-cell DHA about +25%, similar to cooked salmon	32 healthy adults	Algal-oil capsules, 600 mg DHA a day for 2 weeks
⁶	DHA and EPA non-inferior to fish oil at 6 and 14 weeks	74 adults	Microalgal oil versus fish oil

^{5 6 4}

●

Omega-3 index

Higher in trials

DHA plus EPA in red blood cell membranes, as a percentage of all fatty acids.

Low certainty

Results and what it means

Why it was measured

Used as a measure of long-term omega-3 status.

Statistical vs. clinical meaning

No comparison group; shows a rise, not a benefit.

Safety implication

None noted.

Study	Result	People	Product
¹⁶	3.1% to 4.8% (p = 0.009) in vegans starting below 4%	46 vegans	Algal-derived omega-3 supplement (254 mg DHA plus EPA a day) for 4 months

¹⁶

Safety

What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.

Main points to know 4

No source answers whether people with fish or shellfish allergy can use it. Algal oil is not made from fish, but no source read tested or stated whether people with fish or shellfish allergy react to algal oil or to other ingredients in a product. Check the full label, including the capsule shell, and ask an allergist. Not established ¹⁹
It can raise LDL cholesterol. In a review of 11 trials in 485 healthy people, algal DHA lowered triglycerides but raised LDL cholesterol by 0.23 mmol/L (95% CI 0.16 to 0.30) and HDL cholesterol by 0.07 mmol/L. The trials used large amounts. Ask a doctor or pharmacist if your cholesterol is being treated. Meta analysis of trials ⁷
High amounts of EPA plus DHA were linked to more atrial fibrillation in people at high heart risk. A 2026 meta-analysis of 35 trials (114,592 people aged 50 or over) found significantly more new atrial fibrillation only in people at high heart-disease risk taking more than 1,500 mg a day of EPA plus DHA (odds ratio 1.43, absolute difference 0.8%). Lower amounts or low-risk groups showed no significant rise. Algal oil was not analysed alone. Meta analysis of trials ²
Bleeding: no overall rise with omega-3, but high-dose purified EPA showed a modest one. A 2024 meta-analysis of 11 trials (120,643 people) found no overall increase in bleeding (rate ratio 1.09, 95% CI 0.91 to 1.31). High-dose purified EPA showed about 50% higher relative risk and a 0.6% higher absolute risk. Algal oil was not studied alone. Tell your surgical team about supplements before an operation and ask a pharmacist if you take blood thinners. Meta analysis of trials ¹²

Side effects 4

Effect	How often	Severity and recovery	Evidence
Unpleasant taste, bad breath, bad-smelling sweat, headache, heartburn, nausea, diarrhoea NCCIH describes these for omega-3 supplements in general.	NCCIH says omega-3 side effects are usually mild. The algal-oil trials reported algal DHA as generally well tolerated.	Usually mild Not stated in the sources read.	Authoritative guidance and randomised trials ^{19 5 4}
Higher LDL cholesterol Large amounts were used in the pooled trials.	LDL cholesterol rose by 0.23 mmol/L on average in 11 trials of healthy people.	Not stated; a blood-test change Not stated in the abstract.	Meta analysis of trials ⁷
Atrial fibrillation (irregular heartbeat) Omega-3 in general; algal oil was not analysed alone.	Seen significantly more only in high-risk people taking more than 1,500 mg a day of EPA plus DHA: odds ratio 1.43 (95% CI 1.14 to 1.79), absolute difference 0.8%.	Can be serious Not stated in the abstract.	Meta analysis of trials ²
Bleeding Not studied for algal oil alone.	No overall rise (rate ratio 1.09). High-dose purified EPA: about 50% higher relative risk, 0.6% absolute.	Modest Not stated in the abstract.	Meta analysis of trials ¹²

Liver

No source read described liver injury from algal oil. The liver-safety database LiverTox was not opened. In a 90-day rat study, higher liver weights seen at the top level were also seen with fish oil and were not considered adverse by the authors. ¹¹

How often. No frequency was found.

Monitoring. No agency monitoring advice was found.

This is a safety connection. It is not evidence that Algal (algae) oil supports liver health.

Medicines and supplements 4

With	Why it matters	Importance	Evidence	What to do
Blood-thinning and antiplatelet medicines (such as warfarin, aspirin, clopidogrel) drug	Omega-3 fats might affect bleeding; the pooled trials found no overall rise.	A 2024 meta-analysis found no overall extra bleeding with omega-3, and bleeding was not linked to background antiplatelet use; high-dose purified EPA showed a modest rise. Algal oil was not studied alone.	Meta-analysis Moderate certainty ¹²	Ask a pharmacist or doctor if you take blood thinners.
Cholesterol-lowering medicines drug	Not described.	No source read tested algal oil with cholesterol medicines. Algal DHA raised LDL cholesterol in healthy people not on treatment, so a doctor may want to know.	Not established Not enough evidence ⁷	Tell the prescriber you take it.
Heart-rhythm medicines and existing heart-rhythm problems drug	Not described.	Omega-3 in high amounts was linked to more atrial fibrillation in high-risk people. No source read tested algal oil with heart-rhythm medicines.	Meta analysis (omega 3 in general) Low certainty ²	Ask a doctor if you have a heart-rhythm problem.
Other omega-3 products (fish oil, krill oil, cod liver oil) supplement	Each product adds EPA and DHA, so the total adds up.	No source read states a limit for combined products. Cod liver oil also carries vitamins A and D (NCCIH).	Reasoning, not tested Not enough evidence ¹⁹	Add up the label amounts; ask a pharmacist.

Who should check first 6

Situation	Advice	Evidence
Fish or shellfish allergy	Algal oil is not from fish, but no source read answered whether people with fish allergy can use it safely, or whether the capsule shell or other ingredients contain fish. Ask an allergist and read the label.	Not established ¹⁹
Pregnancy	Trials of DHA in pregnancy (including KUDOS) reported no safety concerns, and a Cochrane review found fewer preterm births with omega-3 in general. None of the pregnancy evidence tested algal oil alone. Ask a doctor or midwife before using it.	Randomised trials and systematic review ^{8 13}
Breastfeeding	One trial in 137 breastfeeding women in China gave algal oil DHA for 8 weeks and raised breast milk DHA; the abstract does not describe safety results. Ask a doctor or midwife.	Randomised trial ¹⁷
Children and babies	Trials in UK schoolchildren aged 7 to 9 and in children with cystic fibrosis used algal oil, and the abstracts report no safety problems, but both were small and the DOLAB trials were supplier-funded. No source read gave advice for babies or toddlers. Give supplements to children only on a doctor's or pharmacist's advice.	Randomised trials ^{15 14 3}
High cholesterol, heart disease or heart-rhythm problems	Algal DHA raised LDL cholesterol in healthy people, and high amounts of omega-3 were linked to more atrial fibrillation in high-risk people. Ask a doctor first.	Meta analyses ^{7 2}
Before surgery or with a bleeding disorder	Tell your surgical team about all supplements. Omega-3 did not raise bleeding overall in trials, but algal oil was not studied alone.	Meta-analysis ¹²

Overdose, product quality and regulators

Summary. Algal oil from Schizochytrium sp. was tested in rats and in gene-damage tests with no harmful results. That is animal and laboratory evidence only.

Animal. A 90-day rat feeding study found no treatment-related effects on behaviour, weight, blood tests or urine tests. Higher liver weights and lung changes at the top level were also seen with the fish oil control and were not considered adverse. Gene mutation and chromosome tests were negative.

High dose or long term signals. In people, large pooled amounts raised LDL cholesterol (healthy adults), and high amounts of EPA plus DHA were linked to more atrial fibrillation in high-risk older adults.

Overdose response. No source read described a single large swallow of algal oil. If someone has swallowed a large amount and feels unwell, call poison control or emergency services.

Genotoxicity. Negative in the rat study's gene mutation and chromosome tests.

Quality and contaminants of algal oil products were not researched in a source read.

Product quality. NCCIH says fish liver oils vary in vitamin content from product to product; no source read analysed algal oil products for oxidation, label accuracy or contaminants. ¹⁹

Capsule shells and other ingredients. No source read covered this. Check the label if you avoid animal products.

Body	Action	Date
NCCIH (US National Institutes of Health) (United States)	Algal oils are a vegetarian source of DHA, some with EPA. Omega-3 supplement side effects are usually mild. The page says to talk with health care providers about complementary approaches. source	2024-11
NHS (UK) (United Kingdom)	Lists vegan sources of omega-3 as ground linseed oil, rapeseed oil, chia seeds, hemp seeds and walnuts. It does not mention algal oil. source	2026-06-05

When to get medical help

Wheezing, swelling of the lips or face, hives or trouble breathing after using it (possible allergy): get emergency help.
A new fast, uneven or fluttering heartbeat, chest pain or fainting: get medical help.
Unusual bleeding or bruising, or black stools, especially if you also take blood thinners: see a doctor.
Someone has swallowed a large amount and feels unwell: call poison control or emergency services.

Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.

General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.

Frequently asked questions

What is algal oil?

Algal oil is an oil made from algae. NCCIH calls it a vegetarian source of DHA, and some products also contain EPA. The amounts differ by product, so the label matters.

¹⁹

Is algal oil vegan?

The oil comes from algae, not fish. Capsule shells and other ingredients vary by product and no source we read checked them, so read the label if you avoid animal products.

¹⁹

Is algal oil as good as fish oil?

In small trials it raised blood DHA about as well as cooked salmon or fish oil. These measured blood levels, not health outcomes, and two of the trials are linked to makers of algal oil.

^{5 6 4}

Does algal oil contain EPA?

Some do, according to NCCIH. Others contain mainly DHA. Check the label.

^{19 6}

Does algal oil lower cholesterol?

In a review of 11 trials in healthy people it lowered triglycerides but raised LDL cholesterol and HDL cholesterol. The net effect on the heart was not tested.

⁷

Does it protect the heart?

No trial of algal oil on heart attacks or strokes was found. Large reviews of omega-3, mostly fish oil, found little or no effect on most heart outcomes.

Is algal oil safe with a fish allergy?

No source we read answered this. Algal oil is not made from fish, but ask an allergist and check the whole label.

¹⁹

Is it safe in pregnancy and breastfeeding?

A trial in breastfeeding women raised breast milk DHA, and a Cochrane review found fewer preterm births with omega-3 in general. None of the pregnancy evidence tested algal oil alone. Ask a doctor or midwife.

^{17 13}

Does algal oil help memory or children's learning?

One trial in older adults with mild memory decline found a modest gain on one test. Two school trials in children disagreed: the first was positive only in a subgroup and the repeat found no consistent difference.

^{18 15 14}

What are the side effects?

NCCIH says omega-3 side effects are usually mild: unpleasant taste, bad breath, bad-smelling sweat, headache, heartburn, nausea and diarrhoea. Higher LDL cholesterol was seen in trials.

^{19 7}

Does it interact with medicines?

A 2024 review found no overall extra bleeding with omega-3, but high-dose purified EPA showed a modest rise. Algal oil was not studied alone, and no source we read tested it with cholesterol or heart-rhythm medicines. Ask a pharmacist.

^{12 2}

Does it help with vegan or vegetarian diets?

A review found vegan diets go with lower blood EPA and DHA, and algal DHA improved DHA status. Whether this improves health was not shown.

^{9 16}

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Editorial transparency

Written by: AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
Medical review: None. This page has not been reviewed by a physician or pharmacist.
First published: 2026-10-26
Last substantive update: 2026-10-26
How we research: We read the NCCIH omega-3 page and the NHS vegan-diet page in full, and re-read PubMed abstracts for trials, reviews and meta-analyses. Only abstracts were read for studies. The NIH Office of Dietary Supplements fact sheet was blocked and is marked unread.
How we rate evidence: See "How we rate evidence" in the Evidence tab.
Independence: No product is promoted on this page. No affiliate links are shown. Several algal-oil trials were funded by or linked to makers of algal oil; where the abstract says so, the study table says so.

Sources 21

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

Abdelhamid AS, Brown TJ, Brainard JS, Biswas P, Thorpe GC, Moore HJ, Deane KH, Summerbell CD, Worthington HV, Song F, Hooper L. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease.. Cochrane Database Syst Rev. 2020. PMID 32114706. DOI 10.1002/14651858.CD003177.pub5. (abstract)
Abuknesha NR, O'Keefe JH, Qian F, Tintle NL, Lin Y, Sun Y, Qian HZ, Aisen PS, Albert CM and others. Effects of Omega-3 Fatty Acid Treatment on Risk for Atrial Fibrillation: An Updated Meta-Analysis of 35 Trials including 114 592 Individuals.. Circ Arrhythm Electrophysiol. 2026. PMID 42517224. DOI 10.1161/CIRCEP.125.014785. (abstract)
Alicandro G, Faelli N, Gagliardini R, Santini B, Magazzù G, Biffi A, Risé P, Galli C, Tirelli AS, Loi S, Valmarana L, Cirilli N, Palmas T, Vieni G, Bianchi ML, Agostoni C, Colombo C. A randomized placebo-controlled study on high-dose oral algal docosahexaenoic acid supplementation in children with cystic fibrosis.. Prostaglandins Leukot Essent Fatty Acids. 2013. PMID 23266209. DOI 10.1016/j.plefa.2012.10.002. (abstract)
Arterburn LM, Oken HA, Hoffman JP, Bailey-Hall E, Chung G, Rom D, Hamersley J, McCarthy D. Bioequivalence of Docosahexaenoic acid from different algal oils in capsules and in a DHA-fortified food.. Lipids. 2007. PMID 17713804. DOI 10.1007/s11745-007-3098-5. (abstract)
Arterburn LM, Oken HA, Bailey Hall E, Hamersley J, Kuratko CN, Hoffman JP. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid.. J Am Diet Assoc. 2008. PMID 18589030. DOI 10.1016/j.jada.2008.04.020. (abstract)
Bailey E, Wojcik J, Rahn M, Roos F, Spooren A, Koshibu K. Comparative Bioavailability of DHA and EPA from Microalgal and Fish Oil in Adults.. Int J Mol Sci. 2025. PMID 41096614. DOI 10.3390/ijms26199343. (abstract)
Bernstein AM, Ding EL, Willett WC, Rimm EB. A meta-analysis shows that docosahexaenoic acid from algal oil reduces serum triglycerides and increases HDL-cholesterol and LDL-cholesterol in persons without coronary heart disease.. J Nutr. 2012. PMID 22113870. DOI 10.3945/jn.111.148973. (abstract)
Carlson SE, Colombo J, Gajewski BJ, Gustafson KM, Mundy D, Yeast J, Georgieff MK, Markley LA, Kerling EH, Shaddy DJ. DHA supplementation and pregnancy outcomes.. Am J Clin Nutr. 2013. PMID 23426033. DOI 10.3945/ajcn.112.050021. (abstract)
Chamorro R, Tabilo C, Muñoz Y, Núñez H, Hernández-Rodas MC, Farías C, Echeverría F, Valenzuela R. Vegetarian Diets and Their Effect on n-3 Polyunsaturated Fatty Acids Status in Humans: Systematic Review.. Lipids. 2026. PMID 40958088. DOI 10.1002/lipd.70009. (abstract)
Colombo J, Shaddy DJ, Gustafson K, Gajewski BJ, Thodosoff JM, Kerling E, Carlson SE. The Kansas University DHA Outcomes Study (KUDOS) clinical trial: long-term behavioral follow-up of the effects of prenatal DHA supplementation.. Am J Clin Nutr. 2019. PMID 31004139. DOI 10.1093/ajcn/nqz018. (abstract)
Fedorova-Dahms I, Marone PA, Bailey-Hall E, Ryan AS. Safety evaluation of Algal Oil from Schizochytrium sp.. Food Chem Toxicol. 2011. PMID 20933569. DOI 10.1016/j.fct.2010.09.033. (abstract)
Javaid M, Kadhim K, Bawamia B, Cartlidge T, Farag M, Alkhalil M. Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.. J Am Heart Assoc. 2024. PMID 38742535. DOI 10.1161/JAHA.123.032390. (abstract)
Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega-3 fatty acid addition during pregnancy.. Cochrane Database Syst Rev. 2018. PMID 30480773. DOI 10.1002/14651858.CD003402.pub3. (abstract)
Montgomery P, Spreckelsen TF, Burton A, Burton JR, Richardson AJ. Docosahexaenoic acid for reading, working memory and behavior in UK children aged 7-9: A randomized controlled trial for replication (the DOLAB II study).. PLoS One. 2018. PMID 29462158. DOI 10.1371/journal.pone.0192909. (abstract)
Richardson AJ, Burton JR, Sewell RP, Spreckelsen TF, Montgomery P. Docosahexaenoic acid for reading, cognition and behavior in children aged 7-9 years: a randomized, controlled trial (the DOLAB Study).. PLoS One. 2012. PMID 22970149. DOI 10.1371/journal.pone.0043909. (abstract)
Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement.. Clin Nutr. 2015. PMID 24679552. DOI 10.1016/j.clnu.2014.03.003. (abstract)
Yang Y, Li G, Li F, Xu F, Hu P, Xie Z, Lu X, Ding Y, Wang Z. Impact of DHA from Algal Oil on the Breast Milk DHA Levels of Lactating Women: A Randomized Controlled Trial in China.. Nutrients. 2022. PMID 36014916. DOI 10.3390/nu14163410. (abstract)
Yurko-Mauro K, McCarthy D, Rom D, Nelson EB, Ryan AS, Blackwell A, Salem N Jr, Stedman M. Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline.. Alzheimers Dement. 2010. PMID 20434961. DOI 10.1016/j.jalz.2010.01.013. (abstract)
. NCCIH: Omega-3 Supplements: What You Need To Know (last updated November 2024). . . (full-text)
. NHS: The vegan diet (page last reviewed 5 June 2026). . . (full-text)
. NIH Office of Dietary Supplements: Omega-3 Fatty Acids fact sheet (health professional version). . . (not-read)

Where to buy

Check the label first. Whatever you buy, look for these:

The amount of the active ingredient per serving, not just the front-label claim
A third-party testing mark (USP, NSF or ConsumerLab)
Other ingredients and allergens
Ask a pharmacist about interactions with your medicines

Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.

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Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.