Wellness Goals · Skin condition
Acne: Breakouts, Evaluation and Care
Acne vulgaris · also called Acne, breakouts, pimples, zits, acné, granos
Acne is a common skin condition in which hair follicles become clogged with oil and dead skin cells and bacteria grow in the plugged pores, causing whiteheads, blackheads, red bumps, pus-filled spots and sometimes deep painful lumps. Here is how acne breakouts are evaluated and treated according to the NHS and the American Academy of Dermatology guideline, and what diet, zinc, tea tree oil, green tea, probiotics and other natural options have shown. Evidence for natural options is mostly low or very low, and severe, scarring or mood-affecting acne needs a clinician.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Acne: Breakouts, Evaluation and Care
Acne breakouts happen when pores clog with oil and dead skin cells and bacteria grow in them. Care ranges from gentle washing and pharmacy products to prescription creams and tablets, chosen with a clinician. For natural options, diet, zinc, green tea extract and probiotics have some low-certainty support, tea tree oil is unproven, and scarring, mood effects and pregnancy need a doctor.
What acne is
NIAMS says acne is a common skin condition that happens when hair follicles under the skin become clogged. Oil and dead skin cells plug the pores, and bacteria grow in them. It most often appears on the face, and can also affect the back, chest and shoulders. It is most common in teens and young adults, and in adulthood it is more common in women.
The NHS lists whiteheads, blackheads, papules (raised bumps), pustules (pus-filled bumps), and nodules or cysts (larger, sometimes painful lumps) as the main spot types. Acne can leave scars and can affect mental health.
What drives breakouts
NIAMS lists excess oil, dead skin cell build-up and bacterial growth. Risk factors include rising androgen hormones (as in puberty or pregnancy), family history, and some medicines, including those with hormones, corticosteroids and lithium. The NHS adds hormone changes around periods and menopause and some greasy skin or hair products.
NIAMS says squeezing or picking, scrubbing too hard, pressure from helmets, tight clothes or backpacks, stress, and pollution or humidity can make acne worse. It does not call diet a cause, but says some studies suggest certain foods may worsen it.
How acne is evaluated
According to NIAMS, a provider asks about family history, how long the acne has been present, menstrual cycles where relevant, and current or recently stopped medicines. They examine the skin to identify the spot types and may order blood tests to look for another condition causing the acne. Acne is treated by dermatologists or by primary care providers such as family doctors.
Established care, in general terms
At home, the NHS and NIAMS advise gentle washing with a mild cleanser, removing make-up at night, using non-comedogenic or oil-free products, not picking or scrubbing, loose clothing for body acne, and sunscreen because many acne medicines increase sun sensitivity. A pharmacist can suggest products such as salicylic acid or benzoyl peroxide.
For more stubborn or severe acne, the NHS describes prescription skin treatments (retinoids and antibiotics) and tablets (antibiotics, the combined pill for some people, and isotretinoin). The 2024 American Academy of Dermatology guideline made strong recommendations for benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline, and for oral isotretinoin in acne that is severe, scarring, causes psychosocial burden or fails standard treatment. NIAMS also lists light and laser therapy, peels and other procedures for stubborn scarring. These choices, and any safety checks, belong with a clinician.
What diet, zinc, tea tree oil and other natural options show
The best-supported idea is a lower-glycaemic eating pattern, with a modest effect and some randomised-trial support (low certainty). Dairy is linked with acne in observational studies (very low certainty). Zinc and green tea extract on the skin showed fewer inflamed spots in pooled trials (low certainty). Probiotics, omega-3 and vitamins D and B5 look possibly helpful but the evidence is thin. Tea tree oil, nicotinamide and aloe gel have insufficient evidence, and a 40-study review concluded there is not enough evidence to recommend complementary treatments for acne. See the Health Benefits and Evidence tabs.
At a glance
Traditional uses history, not proof
Studied for research
- Lower-glycaemic eating pattern, low certainty
- Dairy intake (observational link), very low certainty
- Zinc, low certainty
- Green tea extract on the skin, low certainty
- Oral probiotics, low certainty
- Omega-3 fatty acids, very low certainty
- Vitamins D and B5, very low certainty
- Tea tree oil, nicotinamide and aloe gel, insufficient evidence
Main compounds
- Zinc
- Green tea extract
- Tea tree oil
- Probiotics
- Omega-3 fatty acids
- Nicotinamide
- Aloe vera gel
Common forms
- Skin-applied gels and lotions
- Oral supplements
- Eating patterns
Research links: AAD guideline of care for acne vulgaris, 2024 · NHS: Acne · NIAMS: Acne · Diet and acne: a systematic review, 2022 · Oral nutraceuticals for acne, JAMA Dermatology 2023 · Tea tree oil systematic review, 2023 · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Acne (acne vulgaris)
- Common names
- Acne (English); Breakouts, pimples, zits (English); Acné (Spanish); Granos, espinillas (Spanish)
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 |
|---|---|---|---|---|
| Zinc | mineral | Studied as a supplement and skin treatment. 12 | Human data | |
| Green tea extract | plant extract | Studied on the skin and by mouth. 5 | Human data | |
| Tea tree oil | essential oil | Studied on the skin. 4 | Human data | |
| Probiotics | live microbes | Studied by mouth. 6 | Human data | |
| Omega-3 fatty acids | fatty acid | Studied as supplements. 13 | Human data | |
| Nicotinamide | vitamin B3 form | Studied on the skin. 7 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| How acne forms | NIAMS: researchers believe acne can result from excess oil, a build-up of dead skin cells in the pore, and bacterial growth in the pore. Androgen hormones rise in puberty and can enlarge oil glands. 19 | Agency summary | |
| Possible diet pathway | The 2022 review proposes that glycaemic load and dairy influence insulin, IGF-1 and androgens. This is a proposal in the review, not a finding of the studies read. 8 | Proposed |
Isolated compounds versus whole extracts
The studies read tested supplements and extracts, not whole foods; food patterns were studied separately in the diet reviews.
4 low certainty3 very low certainty4 not enough evidence
What was looked at
The 11 benefits and uses checked for Acne: Breakouts, Evaluation and Care, each with how strong the evidence is. Tap one to open it.
- Lower-glycaemic eating patternLow certainty
- Dairy intake (observational link)Very low certainty
- Zinc by mouth or on the skinLow certainty
- Green tea extractLow certainty
- Probiotics by mouthLow certainty
- Omega-3 fatty acidsVery low certainty
- Vitamin D and vitamin B5Very low certainty
- Tea tree oil on the skinNot enough evidence
- Nicotinamide (niacinamide) on the skinNot enough evidence
- Aloe vera gelNot enough evidence
- Complementary treatments as a groupNot enough evidence
Lab markers tracked in the studies
Inflammatory lesion countSerum zincTotal lesion count
What is Acne: Breakouts, Evaluation and Care good for?
The natural and lifestyle approaches that have been studied for acne, and how strong the human evidence is for each. These describe what studies found, not advice to use them. They do not replace the care described in the About tab.
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.
Lower-glycaemic eating pattern
Low certaintyA 2022 systematic review of 34 articles found that eating a high-glycaemic-index diet or a high daily glycaemic load was linked with more acne and more severe acne, and says randomised trials support this. The authors call the effect modest. Diet is a possible influence, not a cure.
3 studiesStudies compared higher and lower glycaemic eating patterns as report…
Studies, doses and limits
What the trials found
Systematic review of 34 articles (searched to late 2021) and a second review of 53 articles from 2009 to 2020 (7 randomised and 4 open-label trials, 42 observational studies).
Results
High glycaemic index and load were positively linked with acne and severity, with some randomised-trial support. The second review also linked fruit, vegetables and fatty acids with less acne.
Effect sizes as reported
Described as modest; no numbers in the abstracts.
Why this rating
Low, the compiler's rating: reviews describe a modest effect, many studies were observational, and the authors call for more randomised trials.
Form and dose studied
Studies compared higher and lower glycaemic eating patterns as reported. No amounts are advised here.
Who was studied
People with acne and healthy comparison groups; effects may depend on sex and ethnicity.
Limits
Mixed study types, one database searched, and the authors say effects may differ by sex and ethnicity. NIAMS says diet does not cause acne but some studies suggest certain foods may make it worse.
Why researchers looked
Foods that raise blood sugar quickly raise insulin, and the authors say insulin, IGF-1 and androgen hormones affect how acne forms.
Proposed mechanism Hypothesis
Proposed in the review: blood sugar and insulin changes alter hormones that drive oil production. This was not tested directly in the studies read.
A proposed mechanism does not show that the effect happens in people.
Cutting out whole food groups without advice can leave gaps in nutrition; ask a doctor or dietitian, especially for teenagers.
Dairy intake (observational link)
Very low certaintyAcross 14 observational studies of 78,529 children, teens and young adults, people who had more milk, yogurt or cheese were more likely to have acne. This shows a link, not that dairy causes acne, and the authors warn of bias.
2 studiesIntakes were as self-reported in surveys.
Studies, doses and limits
What the trials found
Meta-analysis of 14 observational studies (ages 7 to 30) and, separately, the 2022 review, which found dairy evidence mixed.
Results
Any dairy was linked with higher odds of acne (OR 1.25, CI 1.15 to 1.36); milk 1.28; low-fat or skim milk 1.32; yogurt 1.36; cheese 1.22 (CI 1.00 to 1.50). Adjusted results were smaller. The 2022 review found the link mixed and possibly dependent on sex, ethnicity and usual diet.
Effect sizes as reported
OR 1.25 for any dairy
Why this rating
Very low, the compiler's rating: all observational, publication bias reported, and big differences between studies. No randomised trial of removing dairy was read.
Form and dose studied
Intakes were as self-reported in surveys.
Who was studied
Children, adolescents and young adults aged 7 to 30.
Limits
People who report more dairy may differ in other ways. Adjusted links were weaker.
Why researchers looked
Milk contains hormones and growth factors, and researchers wondered whether dairy affects acne.
Proposed mechanism Hypothesis
Proposed: dairy may influence insulin and IGF-1. Not tested in the reviews read.
A proposed mechanism does not show that the effect happens in people.
Children and teenagers need calcium and other nutrients; ask a doctor or dietitian before cutting out dairy.
Zinc by mouth or on the skin
Low certaintyA meta-analysis found people with acne had lower blood zinc than people without, and that people treated with zinc had a larger fall in inflamed spots (papules) than those not treated with zinc, without more side effects. The JAMA Dermatology review of supplements reported stomach and gut side effects with zinc.
3 studiesOral and topical zinc were both studied, alone or with other treatmen…
Studies, doses and limits
What the trials found
Systematic review and meta-analysis of studies of serum zinc and of zinc treatment, oral or topical, alone or added to other treatment. The abstract gives no trial count or numbers.
Results
Lower serum zinc in acne; zinc treatment lowered inflammatory papule count; no significant difference in side effects overall. A separate 42-trial review of oral supplements reported gut side effects with zinc.
Effect sizes as reported
Not given as numbers in the abstract.
Why this rating
Low, the compiler's rating: the abstract gives no numbers or trial sizes, and the two reviews differ on side effects. Low blood zinc does not prove that low zinc causes acne.
Form and dose studied
Oral and topical zinc were both studied, alone or with other treatment. The NHS says a pharmacist can advise on tablet supplements such as zinc. No amounts are advised here.
Who was studied
People with acne.
Limits
Abstract-only reading; mixed forms of zinc and wide differences between trials.
Why researchers looked
Zinc plays a part in skin and immune function, so it has been tried for acne.
Proposed mechanism Not established
Not established in the abstracts read.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab: stomach upset was reported, and zinc supplements can interact with other medicines; ask a pharmacist.
Green tea extract
Low certaintyA meta-analysis of 5 randomised trials (247 people) found green tea extract lowered inflamed spot counts. The benefit came from extract applied to the skin; extract taken by mouth had minimal effect.
2 studiesSkin-applied and oral green tea extract in the trials; products and s…
Studies, doses and limits
What the trials found
Meta-analysis of 5 randomised trials (125 treated, 122 control). The JAMA Dermatology review also listed green tea extract among supplements with possible benefit.
Results
Inflammatory lesions fell by about 9 spots overall (MD -9.38, CI -14.13 to -4.63). On the skin: inflammatory -11.39 and non-inflammatory -32.44 lesions. By mouth: inflammatory -1.40, non-inflammatory no significant change.
Effect sizes as reported
See results
Why this rating
Low, the compiler's rating: only five small trials with different products, from abstracts. Authors call for higher quality trials.
Form and dose studied
Skin-applied and oral green tea extract in the trials; products and strengths varied. Drinking tea was not tested here.
Who was studied
People with acne in five randomised trials.
Limits
Few trials, product differences, and the oral-extract result is much smaller.
Why researchers looked
Green tea contains plant compounds studied for calming inflammation.
Proposed mechanism Hypothesis
Proposed: anti-inflammatory and antioxidant action, per the review. Not tested directly here.
A proposed mechanism does not show that the effect happens in people.
Concentrated green tea extract taken by mouth has been linked to liver problems in other reports; see the green tea extract page and ask a doctor first.
Probiotics by mouth
Low certaintyTwo recent reviews of randomised trials suggest oral probiotics may modestly reduce acne after about 12 weeks, but the trials are few and small and results vary a lot.
3 studiesDifferent probiotic strains and products were used; the abstracts do …
Studies, doses and limits
What the trials found
A 2025 meta-analysis of 9 trials (623 people, 7 pooled) and a 2025 meta-analysis of 3 double-blind trials (231 people).
Results
At 12 weeks: severity grade lower (SMD -1.38, CI -2.69 to -0.08) and total lesions lower (MD -10.4, CI -16.2 to -4.51). The smaller review found a modest drop in inflamed lesions (SMD -0.57) but a range of possible results that included no effect. No serious side effects.
Effect sizes as reported
See results
Why this rating
Low, the compiler's rating (the second review itself says low to moderate): few small trials with different strains and large differences between them.
Form and dose studied
Different probiotic strains and products were used; the abstracts do not name them all.
Who was studied
People with acne in randomised trials.
Limits
Few trials, wide intervals, different products; one review has no funding statement in the record, the other states no external funding.
Why researchers looked
Gut and skin bacteria are thought to affect skin inflammation, and probiotics are used to avoid long antibiotic courses.
Proposed mechanism Hypothesis
Proposed in the reviews: effects through gut and skin microbes. Not tested directly.
A proposed mechanism does not show that the effect happens in people.
No serious side effects were reported in these trials. People with weakened immunity should ask a doctor first.
Omega-3 fatty acids
Very low certaintyReviews report that omega-3 supplements may improve acne in some trials, and a genetic study links higher EPA levels with lower acne risk. The abstracts give few numbers, so the strength of the effect is unclear.
2 studiesSupplements in trials; fish and plant sources are not compared here.
Studies, doses and limits
What the trials found
The 42-trial JAMA Dermatology review of oral supplements and a 2025 Eur J Nutr review combining trials with a genetic analysis.
Results
Fair or good quality studies showed possible benefit of omega-3 for lesion counts or investigator scores. The genetic analysis linked EPA with lower acne risk (OR 0.318, CI 0.102 to 0.991).
Effect sizes as reported
See results
Why this rating
Very low, the compiler's rating: abstracts give no trial numbers, trials were small, and genetic links do not show what happens when someone takes a supplement.
Form and dose studied
Supplements in trials; fish and plant sources are not compared here.
Who was studied
People with acne; genetic analysis in mainly European populations.
Limits
Abstract-only reading, small trials, no direct comparison with standard care.
Why researchers looked
Omega-3 fats are involved in inflammation, and observational reviews linked fatty acids with less acne.
Proposed mechanism Hypothesis
Proposed: calming inflammation. Not tested directly here.
A proposed mechanism does not show that the effect happens in people.
Omega-3 can affect bleeding risk at high amounts and interact with blood thinners; ask a pharmacist.
Vitamin D and vitamin B5
Very low certaintyThe 42-trial review reported possible benefit of vitamins B5 and D from fair or good quality studies. It gave no more detail in its abstract, so this is a thin signal.
1 studiesOral supplements; no amounts advised here.
Studies, doses and limits
What the trials found
One systematic review of oral nutraceuticals (42 trials, 3,346 people).
Results
Possible benefit reported as fewer lesions or better investigator scores. No numbers in the abstract.
Effect sizes as reported
Not given as numbers in the abstract.
Why this rating
Very low, the compiler's rating: one review, abstract only, small studies.
Form and dose studied
Oral supplements; no amounts advised here.
Who was studied
People with acne in randomised trials.
Limits
No product, amount or trial details were read.
Why researchers looked
Both vitamins have been tried for skin inflammation and oil control.
Proposed mechanism Not established
Not established in the abstract read.
A proposed mechanism does not show that the effect happens in people.
Vitamin D in large amounts can build up in the body; ask a pharmacist before taking supplements.
Tea tree oil on the skin
Not enough evidenceA review of 46 trials across many conditions says more evidence is needed to confirm that tea tree oil reduces acne lesions. NCCIH says research suggests it might help but more evidence is needed.
2 studiesProducts and strengths varied between trials; no strength is advised …
Studies, doses and limits
What the trials found
Systematic review of 46 randomised trials (9 in dermatology) and the NCCIH page.
Results
Evidence for acne was not strong enough to confirm benefit. Side effects were reported in 60 percent of included studies and were minor, except at skin strengths of 25 percent or more.
Effect sizes as reported
Not given as numbers for acne
Why this rating
Insufficient, the authors' own conclusion: more and better trials are needed.
Form and dose studied
Products and strengths varied between trials; no strength is advised here.
Who was studied
Mixed groups across 46 trials.
Limits
Poor to modest trial quality.
Why researchers looked
Tea tree oil is traditionally used on skin problems and has germ-fighting activity in the lab.
Proposed mechanism Hypothesis
Proposed: germ-killing and anti-inflammatory effects. Not confirmed in the reviews read.
A proposed mechanism does not show that the effect happens in people.
Skin irritation is the main concern; never swallow it. See the Safety tab.
Nicotinamide (niacinamide) on the skin
Not enough evidenceA Cochrane review found four trials that compared nicotinamide with antibiotic skin treatments; none measured how much patients felt their acne improved, so its benefit could not be judged. The NHS lists niacinamide among supplements a pharmacist can advise on.
2 studiesGel or lotion in the trials; no amounts advised.
Studies, doses and limits
What the trials found
Cochrane review of 49 trials of six skin treatments, 4 of them on nicotinamide.
Results
Compared with clindamycin, withdrawals and minor side effects were probably similar (low-quality evidence). Improvement was not measured.
Effect sizes as reported
Minor side effects vs clindamycin RR 1.20 (CI 0.73 to 1.99)
Why this rating
Insufficient: no usable improvement outcome and only low-quality comparisons with antibiotics.
Form and dose studied
Gel or lotion in the trials; no amounts advised.
Who was studied
Mostly mild to moderate acne, ages 12 to 30.
Limits
Compared only with antibiotics, not with a dummy treatment.
Why researchers looked
Nicotinamide is a form of vitamin B3 used in skin products.
Proposed mechanism Not established
Not established.
A proposed mechanism does not show that the effect happens in people.
Minor skin reactions were similar to clindamycin in low-quality evidence.
Aloe vera gel
Not enough evidenceNCCIH says two small studies suggest aloe gel on the skin, added to other treatment, may improve acne.
1 studiesAloe gel on the skin, combined with other treatment.
Studies, doses and limits
What the trials found
NCCIH summary of two small studies; the studies themselves were not read.
Results
Possible improvement when combined with other treatment.
Effect sizes as reported
Not given.
Why this rating
Insufficient: two small studies, second-hand through the NCCIH page.
Form and dose studied
Aloe gel on the skin, combined with other treatment.
Limits
Studies not read directly.
Why researchers looked
Aloe gel is a common soothing skin product.
Proposed mechanism Not established
Not established.
A proposed mechanism does not show that the effect happens in people.
NCCIH says aloe gel is generally well tolerated but burning, itching, rash and eczema have been reported.
Complementary treatments as a group
Not enough evidenceA meta-analysis of 40 studies across acne, eczema and psoriasis found the acne results could not be told apart from no change and concluded there is not enough evidence to support or recommend these treatments.
1 studiesMany different treatments.
Studies, doses and limits
What the trials found
Meta-analysis of 40 studies in acne, atopic dermatitis and psoriasis.
Results
Acne total lesion count SMD 3.78 (CI -0.01 to 7.57) and 0.58 (CI -6.99 to 8.15).
Effect sizes as reported
See results
Why this rating
Insufficient, the authors' conclusion.
Form and dose studied
Many different treatments.
Who was studied
People with acne, eczema or psoriasis.
Limits
Studies differed in design, size, measures and length.
Why researchers looked
Many people try plant, supplement and other complementary treatments for skin.
Proposed mechanism Not established
Not established; the group contains many different treatments.
A proposed mechanism does not show that the effect happens in people.
Natural does not mean harmless; tell a doctor or pharmacist about everything you use.
Connections to the rest of health
How Acne: Breakouts, Evaluation and Care 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
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Skin Health | Low certainty | Lower-glycaemic eating pattern: A 2022 systematic review of 34 articles found that eating a high-glycaemic-index diet or a high daily glycaemic load was linked with more acne and more severe acne, and says randomised trials support this. The authors call the effect modest. Diet is a possible influence, not a cure. Zinc by mouth or on the skin: A meta-analysis found people with acne had lower blood zinc than people without, and that people treated with zinc had a larger fall in inflamed spots (papules) than those not treated with zinc, without more side effects. The JAMA Dermatology review of supplements reported stomach and gut side effects with zinc. | 8 1 19 12 10 17 5 6 11 13 4 16 7 15 2 | |
| Skin Health | Very low certainty | Dairy intake (observational link): Across 14 observational studies of 78,529 children, teens and young adults, people who had more milk, yogurt or cheese were more likely to have acne. This shows a link, not that dairy causes acne, and the authors warn of bias. | 3 8 |
B. Body systems
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Inflammatory lesion count | Biological association | Low certainty | Measured in trials: fell with zinc and with green tea extract on the skin in pooled trials. A lab change is not the same as a health benefit. | 5 12 |
| Serum zinc | Biological association | Low certainty | Measured in trials: lower in people with acne than in controls. A lab change is not the same as a health benefit. | 12 |
| Total lesion count | Biological association | Low certainty | Measured in trials: fell with probiotics at 12 weeks. A lab change is not the same as a health benefit. | 6 11 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Zinc | Biological association | Human | Studied as a supplement and skin treatment. | 12 |
| Green tea extract | Biological association | Human | Studied on the skin and by mouth. | 5 |
| Tea tree oil | Biological association | Human | Studied on the skin. | 4 |
| Probiotics | Biological association | Human | Studied by mouth. | 6 |
| Omega-3 fatty acids | Biological association | Human | Studied as supplements. | 13 |
| Nicotinamide | Biological association | Human | Studied on the skin. | 7 |
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 31, 2026).
Evidence at a glance: what the research found for 11 outcomes
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.
The evidence
The research centre for Acne: Breakouts, Evaluation and Care. 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 searched PubMed, read the abstract of every review and guideline cited, and read the NHS, NIAMS, NCCIH and MedlinePlus pages through a tool that summarises pages. Certainty ratings are the compiler's own reading unless a review gives its own grade.
Study library: every study we checked 20
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Dall'Oglio 2021 Diet and acne: review of the evidence from 2009 to 2020 Int J Dermatol · PMID 33462816 · DOI |
Systematic review |
53 53 articles: 11 interventional studies (7 randomised, 4 open-label) and 42 observational studies |
Dietary factors (glycaemic load, dairy, fat, chocolate, fruit, vegetables, fatty acids) · vs Lower intake or no intake |
Acne-promoting factors were high glycaemic index or load foods, dairy products, fatty food and chocolate; acne-protective factors were fatty acids, fruit and vegetables. The role of specific parts of foods, such as full-fat versus skim milk or dark versus milk chocolate, was unresolved. Not given as numbers in the abstract Methods, limits and fundingOutcomes: Acne development, duration and severity Limitations: Most studies were observational, so they show links, not cause. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Jones 2021 Complementary and alternative medicine treatments for common skin diseases: A systematic review and meta-analysis JAAD Int · PMID 34409356 · DOI |
Systematic review meta analysis |
40 studies in acne, atopic dermatitis and psoriasis | Complementary and alternative treatments · vs Placebo, no treatment or other treatment |
The pooled results for acne total lesion count had confidence intervals that included no change (SMD 3.78, 95% CI -0.01 to 7.57; and 0.58, CI -6.99 to 8.15). The authors conclude there is insufficient evidence to support or recommend these treatments for acne, atopic dermatitis and psoriasis. Acne total lesion count SMD 3.78 (CI -0.01 to 7.57) and 0.58 (CI -6.99 to 8.15) Methods, limits and fundingOutcomes: Lesion counts and severity scores Limitations: Studies differed in design, size, measures and length, which limits what can be generalised. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Juhl 2018 Dairy Intake and Acne Vulgaris: A Systematic Review and Meta-Analysis of 78,529 Children, Adolescents, and Young Adults Nutrients · PMID 30096883 · DOI |
Meta analysis observational |
78529 14 observational studies, ages 7 to 30 (23,046 with acne, 55,483 controls) |
Dairy intake (milk, yogurt, cheese) · vs Less than weekly or no intake |
Any dairy was linked with higher odds of acne. Milk was linked with higher odds, more so with one glass a day or more; yogurt and cheese showed weaker links. Adjusted results were smaller than unadjusted ones. Any dairy OR 1.25; any milk OR 1.28; low-fat or skim milk OR 1.32; yogurt OR 1.36; cheese OR 1.22 (CI 1.00 to 1.50) Methods, limits and fundingOutcomes: Odds of having acne Limitations: The authors warn of publication bias and wide differences between studies. Observational data cannot show that dairy causes acne. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Kairey 2023 Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health: a systematic review of randomized controlled trials Front Pharmacol · PMID 37033604 · DOI |
Systematic review |
46 randomised trials across dentistry, dermatology (9), infection, eye care and foot care | Tea tree oil, mostly applied to the skin or mouth · vs Any control |
For acne, the authors say more evidence is needed to confirm benefits for reducing lesions and severity. Side effects were reported in 60 percent of the included studies and were minor, except where tea tree oil was applied to the skin at strengths of 25 percent or more. Research quality was poor to modest. Not given as numbers for acne Methods, limits and fundingOutcomes: Clinical outcomes and side effects Limitations: Small trials, poor to modest quality, many different products and strengths. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Kim 2021 The effects of green tea on acne vulgaris: A systematic review and meta-analysis of randomized clinical trials Phytother Res · PMID 32812270 · DOI |
Systematic review meta analysis |
247 5 randomised trials (125 treated, 122 control) of green tea extract in acne |
Green tea extract, applied to the skin or taken by mouth · vs Control groups |
Green tea extract overall lowered inflammatory lesion counts. By route: applied to the skin it lowered both inflammatory and non-inflammatory lesions; taken by mouth it had minimal effect. No significant side effects were reported with skin use. Inflammatory lesions MD -9.38 (CI -14.13 to -4.63). Skin use: inflammatory -11.39 (CI -15.91 to -6.86), non-inflammatory -32.44 (CI -39.27 to -25.62). Mouth: inflammatory -1.40 (CI -2.50 to -0.30) Methods, limits and fundingOutcomes: Inflammatory and non-inflammatory lesion counts Limitations: Only five trials, run with different products and strengths. The authors call for higher quality trials. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Lin 2025 Efficacy of oral probiotics in patients with acne: a systematic review and meta-analysis of randomized trials Clin Exp Dermatol · PMID 40832719 · DOI |
Systematic review meta analysis |
623 9 randomised trials (623 people), 7 in the pooled analysis |
Oral probiotics · vs Placebo or other treatment |
After 4 weeks there were only slight differences. After 12 weeks, probiotics lowered the severity grade and the total lesion count compared with control, and improved skin hydration and sebum content. No major side effects were reported. At 12 weeks: severity SMD -1.38 (CI -2.69 to -0.08); total lesions MD -10.4 (CI -16.2 to -4.51) Methods, limits and fundingOutcomes: Severity grade, lesion counts, skin hydration, sebum Limitations: Small trials using different strains; the severity result has a wide interval close to no effect. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Liu 2020 Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne Cochrane Database Syst Rev · PMID 32356369 · DOI |
Systematic review meta analysis |
3880 49 randomised trials (3,880 people), mostly mild to moderate acne, ages 12 to 30, mostly female |
Skin treatments including nicotinamide · vs Other skin treatments, placebo or no treatment |
Four nicotinamide trials compared it with clindamycin or erythromycin and none measured self-assessed improvement. Low-quality evidence showed there may be no difference in withdrawals or minor side effects against clindamycin. Overall the reviewers say risk of bias and imprecision limit confidence. Nicotinamide vs clindamycin, minor side effects RR 1.20 (CI 0.73 to 1.99), low quality Methods, limits and fundingOutcomes: Self-assessed improvement, withdrawals, minor side effects Limitations: No trial of nicotinamide against placebo gave a usable improvement outcome. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Meixiong 2022 Diet and acne: A systematic review JAAD Int · PMID 35373155 · DOI |
Systematic review |
34 articles on diet and acne, searched in MEDLINE in late 2021 | Diet patterns (glycaemic content, dairy) · vs Lower intake or no intake |
High glycaemic index and higher daily glycaemic load were positively linked with acne and acne severity, an observation the authors say is supported by randomised trials. They call the effect modest. Evidence on dairy was mixed and may depend on sex, ethnicity and usual diet; dairy may have worsened acne in some groups where a Western diet is common. The authors say more randomised trials are needed. Not given as numbers in the abstract Methods, limits and fundingOutcomes: Link between glycaemic and dairy intake and acne onset or severity Limitations: Only English-language papers from one database; mixed study designs; effects may differ by sex and ethnicity. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Reynolds 2024 Guidelines of care for the management of acne vulgaris J Am Acad Dermatol · PMID 38300170 · DOI |
Clinical guideline |
People with acne vulgaris aged about 9 years and older (adults, adolescents, preadolescents) | Medical treatments (topical and oral) and combinations · vs Varies by recommendation |
The work group made 18 evidence-based recommendations and 5 good practice statements. Strong recommendations: benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline. Oral isotretinoin is strongly recommended for acne that is severe, causes psychosocial burden or scarring, or fails standard oral or topical therapy. Conditional recommendations cover topical clascoterone, salicylic acid and azelaic acid, and oral minocycline, sarecycline, combined oral contraceptive pills and spironolactone. Good practice statements: combine topical treatments with different actions, limit systemic antibiotic use, combine systemic antibiotics with topical treatment, and consider steroid injections into larger lesions. 18 recommendations and 5 good practice statements Methods, limits and fundingOutcomes: Strength of recommendations for acne treatments Limitations: Based on the best evidence available at the time of its review. The abstract does not describe natural or diet options. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Shields 2023 Safety and Effectiveness of Oral Nutraceuticals for Treating Acne: A Systematic Review JAMA Dermatol · PMID 37878272 · DOI |
Systematic review |
3346 42 randomised trials (3,346 people) of oral vitamins and minerals, botanical extracts, prebiotics and probiotics in acne |
Oral supplements (vitamins, minerals, plant extracts, probiotics, omega-3) · vs Placebo or other treatment |
Studies of fair or good quality showed possible benefit of vitamins B5 and D, green tea extract, probiotics and omega-3 fatty acids, most often as fewer lesions or better investigator scores. Side effects were rare for most products, but stomach and gut side effects were reported with zinc. The authors call the role of supplements possible and note many studies were small. Not given as numbers in the abstract Methods, limits and fundingOutcomes: Lesion counts, investigator global assessment, quality of life, side effects Limitations: Many studies were small; products and amounts varied; the abstract does not give per-product numbers. Funded in part by NIH, per the record (Research Support, N.I.H., Extramural). Funding and conflicts: Research support from the US National Institutes of Health is listed in the record. Read: abstract |
| Tjiu 2025 Oral Probiotics in Acne vulgaris: A Systematic Review and Meta-Analysis of Double-Blind Randomized Clinical Trials Medicina (Kaunas) · PMID 41470154 · DOI |
Systematic review meta analysis |
231 3 double-blind randomised trials (231 people) |
Oral probiotics for at least 4 weeks · vs Placebo or standard therapy |
A modest drop in inflammatory lesions favoured probiotics, but results varied a lot between trials, and the range of effects a future study might find included no meaningful effect. No serious side effects. The authors rate certainty low to moderate. SMD -0.57 (CI -0.94 to -0.21); I-squared 72%; prediction interval -1.25 to 0.11 Methods, limits and fundingOutcomes: Inflammatory lesion counts, adverse events Limitations: Only three trials and wide differences between them. Funding and conflicts: Stated: no external funding. Read: abstract |
| Yee 2020 Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis Dermatol Ther · PMID 32860489 · DOI |
Systematic review meta analysis |
People with acne in studies of serum zinc and in trials of oral or topical zinc | Oral or topical zinc, alone or added to other treatment · vs Placebo, no zinc, or other treatment |
People with acne had lower serum zinc than controls. People treated with zinc had a larger fall in inflammatory papule count than those not treated with zinc, with no significant difference in side effects. The authors conclude zinc is effective, mainly for inflammatory papules, alone or as an add-on. Not given as numbers in the abstract Methods, limits and fundingOutcomes: Serum zinc; inflammatory papule count; side effects Limitations: The abstract gives no numbers, trial counts or doses. Lower blood zinc in acne does not show that low zinc causes acne. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| Zhang 2025 Exploring clinical and genetic evidence in association between unsaturated fatty acids and acne Eur J Nutr · PMID 40106045 · DOI |
Systematic review plus genetic analysis |
Randomised trials of unsaturated fatty acid supplements in acne, plus a genetic analysis in mainly European populations | Omega-3 and omega-6 fatty acids as supplements · vs Control groups |
The authors report that the trials they combined found fatty acid supplements improved acne. The genetic analysis linked higher EPA and arachidonic acid with lower acne risk and dihomo-gamma-linolenic acid with higher risk. They suggest omega-3 may be protective and some omega-6 patterns may promote acne. Genetic analysis: EPA OR 0.318 (CI 0.102 to 0.991) Methods, limits and fundingOutcomes: Acne outcomes; genetic links with blood fatty acids Limitations: The abstract gives no trial numbers or sizes for the clinical part; the genetic analysis is based on European populations and does not prove cause in an individual. Funding and conflicts: No funding or conflict statement in the record read. Read: abstract |
| s-medlineplus-isotretinoin MedlinePlus (NIH): Isotretinoin (revised 15 August 2018) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nccih-aloe NCCIH: Aloe Vera (updated February 2025) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nccih-tea-tree NCCIH: Tea Tree Oil (updated April 2025) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nhs-acne NHS: Acne (last reviewed 22 September 2026) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nhs-acne-treatment NHS: Acne, treatment (last reviewed 22 September 2026) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-niams-acne NIAMS: Acne (reviewed July 2023) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-niams-treatment NIAMS: Acne, diagnosis, treatment and steps to take (reviewed July 2023) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No head-to-head trial of natural options against standard acne care was read.
- No randomised trial of removing dairy was read.
- Abstracts for the zinc and diet reviews give few numbers.
- Primary trials of omega-3, vitamin D and vitamin B5 were not read.
- Pregnancy warnings for acne medicines were not found on the NHS acne pages; the statement here rests on an older MedlinePlus page.
- Long-term safety of supplements in teenagers was not found.
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".
Other 3
Inflammatory lesion count
Fell with zinc and with green tea extract on the skin in pooled trials in trials
The number of red, raised, inflamed spots (papules and pustules).
Low certaintyResults and what it means
Why it was measured
The main way trials measure whether acne has improved.
Statistical vs. clinical meaning
A direct, countable measure, but trials differ in how they count.
Serum zinc
Lower in people with acne than in controls in trials
The level of zinc in the blood.
Low certaintyResults and what it means
Why it was measured
To see whether people with acne have different zinc status.
Statistical vs. clinical meaning
A link only; it does not show that low zinc causes acne or that supplements are needed.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Mean serum zinc was significantly lower in people with acne. | People with acne and controls | Not an intervention |
Total lesion count
Fell with probiotics at 12 weeks in trials
All spots counted together.
Low certaintyResults and what it means
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 6
- See a doctor if acne is severe, deep, painful or scarring. The NHS advises seeing a GP if self-care has not helped, if there are many spots or spots that are deep, painful or leaving scars, if skin is hot, swollen and red (possible infection; redness is harder to see on brown and black skin), or if acne is affecting mental health. A GP may prescribe treatment or refer to a skin specialist (dermatologist). Health agency guidance 17
- Picking and scrubbing cause scars and flares. The NHS and NIAMS say squeezing or picking can cause scars or dark marks and that scrubbing irritates skin and can make acne worse. NIAMS adds that people of colour may get dark patches after acne heals and that sunscreen helps because many acne medicines make skin more sun-sensitive. Health agency guidance 17 20
- Acne can affect mood. The NHS says acne can contribute to anxiety, depression and low self-esteem and advises seeing a GP if it affects mental health. NIAMS advises talking to a doctor if acne causes embarrassment, shyness or anxiety. Health agency guidance 17 20
- Pregnancy and strong prescription acne medicines. MedlinePlus (NIH, 2018 revision) says isotretinoin must not be taken by anyone who is pregnant or may become pregnant, because of a high risk of pregnancy loss, early birth, death shortly after birth or birth defects, and that it is dispensed under a pregnancy-prevention programme. It also reports mood and mental health changes, including depression and suicidal thoughts, and tells people to call a doctor right away about sadness, irritability or thoughts of self-harm. The NHS acne pages read do not give pregnancy warnings, so anyone pregnant, trying to conceive or breastfeeding should ask a doctor or pharmacist before using any acne product, natural or not. Health agency guidance (older page) 14 18
- Tea tree oil: irritation, and never swallow it. NCCIH says most people can use tea tree products on the skin without problems, but some get redness or irritation, more likely if the product is old or has been exposed to heat, light or air. It says tea tree oil should not be swallowed, because swallowing can cause confusion, unsteadiness and coma. The 46-trial review found minor skin side effects were common and stronger at 25 percent or more. Health agency guidance and systematic review 16 4
- Supplements: gut upset and quality. The JAMA Dermatology review reported stomach and gut side effects with zinc and rare side effects for most other supplements, from small trials. Supplements are not tested for acne safety the way prescription medicines are, and the reviews do not cover long-term use. Systematic review 10
Side effects 3
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Stomach and gut upset | Reported with zinc in the supplement review; no rate in the abstract. | Not graded in the abstract | Systematic review of randomised trials 10 |
| Skin redness, burning, itching, rash | Occasionally with aloe gel; side effects in 60 percent of tea tree oil studies. | Mostly minor | Health agency guidance and systematic review 15 4 16 |
| Irritation, burning or redness from standard skin treatments | No rate given | Mild to moderate | Health agency guidance 20 |
Medicines and supplements 2
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Prescription acne medicines prescription | No study found. | No interaction study of the natural options with acne medicines was read. Absence of a study is not proof of safety. | Absence of evidence Not enough evidence 20 | Tell your doctor or pharmacist about every supplement, tea extract or skin product you use, because some acne medicines make skin more sensitive or irritated. |
| Other medicines and supplements (zinc, omega-3, green tea extract) supplement | Not covered in the sources read. | The sources read do not test interactions. Pharmacists keep the up-to-date interaction details. | Absence of evidence Not enough evidence 10 | Ask a pharmacist before adding supplements, especially if you take regular medicines. |
Who should check first 4
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy, trying to conceive or breastfeeding | Ask a doctor or pharmacist before using any acne treatment. Isotretinoin in particular must not be taken in pregnancy (MedlinePlus, 2018). NCCIH says topical tea tree oil products may be safe in pregnancy and breastfeeding, but that is hedged and not a reason to skip asking. | Health agency guidance 14 16 |
| Severe, cystic or scarring acne | Do not self-treat. The AAD guideline strongly recommends oral isotretinoin for acne that is severe, causes scarring or psychosocial burden, or fails standard treatment, which needs a clinician. | Clinical guideline 9 17 |
| History of depression or low mood | Tell the clinician before starting prescription acne tablets, and see a doctor if acne is affecting mood. | Health agency guidance 14 17 |
| Known allergy to a product (tea tree oil, aloe) | Stop the product if skin burns, itches or comes up in a rash. | Health agency guidance 15 16 |
Overdose, product quality and regulators
| Body | Action | Date |
|---|---|---|
| NHS (England) (United Kingdom) | Advises gentle washing twice a day, non-comedogenic products, no picking or scrubbing, pharmacy options such as salicylic acid or benzoyl peroxide, and seeing a GP for severe or scarring acne or if mental health is affected. Lists prescription skin treatments (tretinoin, adapalene, clindamycin, erythromycin) and tablets (doxycycline, lymecycline, the combined pill, isotretinoin). source | 2026-09-22 |
| American Academy of Dermatology (United States) | 2024 guideline: strong recommendations for benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline; oral isotretinoin for severe, scarring or treatment-resistant acne. source | 2024 |
When to get medical help
- Skin that is hot, swollen, red and painful (possible infection; redness is harder to see on brown and black skin): see a GP.
- Deep, painful lumps or spots that leave scars: see a doctor rather than self-treating.
- Low mood, anxiety or thoughts of self-harm: contact a doctor or local emergency or crisis service right away.
- A rash, swelling or trouble breathing after a product: stop it and seek medical help.
- Swallowing tea tree oil: contact 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 acne?
NIAMS says acne happens when hair follicles become clogged with oil and dead skin cells, and bacteria grow in the plugged pores. It usually affects the face but can also appear on the back, chest and shoulders.
What are the types of acne spots?
The NHS lists whiteheads, blackheads, papules, pustules, and larger nodules or cysts, and says acne can leave scars.
How is acne evaluated?
What does established acne care look like?
The NHS describes gentle washing, pharmacy products such as salicylic acid or benzoyl peroxide, and prescription skin treatments and tablets for more severe acne. The 2024 American Academy of Dermatology guideline made strong recommendations for benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline. A clinician chooses the treatment.
Does diet cause breakouts?
Does dairy make acne worse?
A meta-analysis of 14 observational studies found more acne in people who reported more dairy (OR 1.25), but it warns of bias, and observational data cannot show cause.
Does zinc help acne?
Does tea tree oil work for acne?
Does green tea help acne?
A meta-analysis of five trials found extract applied to the skin lowered lesion counts, while extract taken by mouth had minimal effect. Trials were few and small.
Do probiotics, omega-3 or vitamin D help acne?
Will washing or scrubbing more clear acne?
No. The NHS recommends gentle washing twice a day and says scrubbing can irritate skin and make acne worse; it also advises not to pick or squeeze spots.
When should I see a doctor about acne?
The NHS advises seeing a GP if self-care has not helped, if there are many spots or deep, painful or scarring ones, if skin is hot, swollen and red, or if acne affects your mental health.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-31
- Last substantive update
- 2026-10-31
- How we research
- We searched PubMed, read the abstract of every review and guideline cited, and read the NHS, NIAMS, NCCIH and MedlinePlus pages through a tool that summarises pages. Certainty ratings are the compiler's own reading unless a review gives its own grade.
- 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.
Sources 20
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Dall'Oglio F, Nasca MR, Fiorentini F, Micali G. Diet and acne: review of the evidence from 2009 to 2020. Int J Dermatol. 2021. PMID 33462816. DOI 10.1111/ijd.15390. (abstract)
- Jones VA, Patel PM, Wilson C et al.. Complementary and alternative medicine treatments for common skin diseases: A systematic review and meta-analysis. JAAD Int. 2021. PMID 34409356. DOI 10.1016/j.jdin.2020.11.001. (abstract)
- Juhl CR, Bergholdt HKM, Miller IM et al.. Dairy Intake and Acne Vulgaris: A Systematic Review and Meta-Analysis of 78,529 Children, Adolescents, and Young Adults. Nutrients. 2018. PMID 30096883. DOI 10.3390/nu10081049. (abstract)
- Kairey L, Agnew T, Bowles EJ et al.. Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health: a systematic review of randomized controlled trials. Front Pharmacol. 2023. PMID 37033604. DOI 10.3389/fphar.2023.1116077. (abstract)
- Kim S, Park TH, Kim WI et al.. The effects of green tea on acne vulgaris: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. 2021. PMID 32812270. DOI 10.1002/ptr.6809. (abstract)
- Lin HW, Tam KW, Huang YC. Efficacy of oral probiotics in patients with acne: a systematic review and meta-analysis of randomized trials. Clin Exp Dermatol. 2025. PMID 40832719. DOI 10.1093/ced/llaf388. (abstract)
- Liu H, Yu H, Xia J et al.. Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne. Cochrane Database Syst Rev. 2020. PMID 32356369. DOI 10.1002/14651858.CD011368.pub2. (abstract)
- Meixiong J, Ricco C, Vasavda C, Ho BK. Diet and acne: A systematic review. JAAD Int. 2022. PMID 35373155. DOI 10.1016/j.jdin.2022.02.012. (abstract)
- Reynolds RV, Yeung H, Cheng CE et al.. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024. PMID 38300170. DOI 10.1016/j.jaad.2023.12.017. (abstract)
- Shields A, Ly S, Wafae B et al.. Safety and Effectiveness of Oral Nutraceuticals for Treating Acne: A Systematic Review. JAMA Dermatol. 2023. PMID 37878272. DOI 10.1001/jamadermatol.2023.3949. (abstract)
- Tjiu JW, Lu CF. Oral Probiotics in Acne vulgaris: A Systematic Review and Meta-Analysis of Double-Blind Randomized Clinical Trials. Medicina (Kaunas). 2025. PMID 41470154. DOI 10.3390/medicina61122152. (abstract)
- Yee BE, Richards P, Sui JY, Marsch AF. Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis. Dermatol Ther. 2020. PMID 32860489. DOI 10.1111/dth.14252. (abstract)
- Zhang L, Li Y, Pu Y et al.. Exploring clinical and genetic evidence in association between unsaturated fatty acids and acne. Eur J Nutr. 2025. PMID 40106045. DOI 10.1007/s00394-025-03647-4. (abstract)
- . MedlinePlus (NIH): Isotretinoin (revised 15 August 2018). . . (full-text)
- . NCCIH: Aloe Vera (updated February 2025). . . (full-text)
- . NCCIH: Tea Tree Oil (updated April 2025). . . (full-text)
- . NHS: Acne (last reviewed 22 September 2026). . . (full-text)
- . NHS: Acne, treatment (last reviewed 22 September 2026). . . (full-text)
- . NIAMS: Acne (reviewed July 2023). . . (full-text)
- . NIAMS: Acne, diagnosis, treatment and steps to take (reviewed July 2023). . . (full-text)
