Omega-3, Kidney Disease and Fatty Liver (NAFLD): What Is Known

What systematic reviews and the AASLD liver guidance say about omega-3 in fatty liver disease and in chronic kidney disease, and why both conditions need clinician-led care.

Content last updated October 22, 2026. This page has not been medically reviewed.

Quick answer

If you have kidney or liver disease, decisions about omega-3 belong with your kidney or liver team. Reviews of trials in fatty liver (NAFLD) report some improvement in liver blood tests or ultrasound fat, but the American Association for the Study of Liver Diseases (AASLD) 2023 guidance lists n-3 fatty acids among drugs not found to have liver-specific benefits. [1] In chronic kidney disease (CKD), reviews found low or very low certainty evidence, with benefits for some outcomes in some groups and uncertainty about bleeding. [2] This page is information only.

Terms used by the sources

NAFLD (nonalcoholic fatty liver disease, also called MASLD) and NASH (the form with liver inflammation and scarring, also called MASH) are the terms used by NIDDK, which says doctors recommend weight loss to treat NAFLD. [3] AASLD guidance covers both. [1]
GGT, AST and ALT are blood tests of liver enzymes. A change in these tests is a lab marker, not proof of better liver health.
ESKD is end-stage kidney disease; AVF and AVG are two types of dialysis access. [4]
Evidence labels used here: "mixed" (trials disagree), "insufficient evidence" (too few or weak trials), "no good evidence of benefit", "biomarker change".

What research found: fatty liver

Question	What the source found	Strength of evidence
Liver enzymes and fat, 2025 meta-analysis	20 trials (1,615 adults): lower GGT and better ultrasound-assessed steatosis; no significant effect on AST, ALT, MRI-measured fat, stiffness or biopsy findings. More adverse events overall than controls. [5]	Mixed; some biomarker change
Liver fat, 2020 meta-analysis	22 trials (1,366 people): liver fat improved (pooled risk ratio 1.52, 95% CI 1.09 to 2.13), with lower triglycerides. [6]	Mixed to promising
Guidance view	AASLD 2023: n-3 polyunsaturated fatty acids were among other drugs "not found to have liver-specific benefits." [1]	Guideline statement
High triglycerides in NAFLD	AASLD: hypertriglyceridemia can be managed through lifestyle changes and omega-3 fatty acids, icosapent ethyl or fibrates; for triglycerides above 500 mg/dL, fibrates or a combination with prescription-grade omega-3. [1]	Clinician-led

The two meta-analyses searched at different dates (March 2020 and November 2024) and reported different outcomes. Neither shows that omega-3 treats fatty liver disease. NIDDK also advises talking with your doctor before using dietary supplements and warns that some herbal remedies can damage the liver. [3] See liver safety and supplements.

What research found: kidney disease

Question	What the source found	Strength of evidence
Heart and kidney outcomes in CKD	60 supplement trials (4,129 people, median follow-up 6 months): fewer cardiovascular deaths in hemodialysis (RR 0.45) and less ESKD in CKD without dialysis (RR 0.30); little or no difference in all-cause death or transplant outcomes. [2]	Low to very low certainty
Bleeding and stomach effects	Bleeding (RR 1.40, 95% CI 0.78 to 2.49) and gastrointestinal effects were uncertain in the same review. [2]	Insufficient evidence
Dialysis fistula (AVF)	Cochrane: probably little or no difference in losing patency over 12 months (RR 1.01). [4]	Moderate certainty
Dialysis graft (AVG)	Cochrane: very uncertain; there may be more mild stomach effects such as bloating or a fishy aftertaste. [4]	Very low certainty

We did not find a kidney guideline statement on omega-3 supplements in the pages we read, so none is described here. For a related page, see minerals, supplements and kidney disease.

Frequently asked questions

Is fish oil good for fatty liver?

Meta-analyses reported improvements in some liver markers or ultrasound findings, but not in liver biopsy findings, and AASLD 2023 lists n-3 fatty acids among drugs not found to have liver-specific benefits. [5][1]

Can omega-3 harm the kidneys?

The review abstracts we read did not report kidney harm, but bleeding and stomach effects were uncertain in CKD. [2] Kidney disease changes medicine safety, so ask your kidney team.

Does omega-3 help people on dialysis?

A review found low or very low certainty evidence of fewer cardiovascular deaths on hemodialysis, and a Cochrane review found probably no difference in fistula patency. [2][4]

Should I take omega-3 if my triglycerides are high and I have fatty liver?

AASLD says high triglycerides can be managed with lifestyle changes, omega-3 fatty acids, icosapent ethyl or fibrates; your clinician chooses the approach. [1]

Do liver tests change with omega-3?

Some trials reported lower GGT, but no significant change in AST or ALT in the 2025 meta-analysis. [5] Tell your clinician about any supplement before blood tests.

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

Limits and uncertainty

Findings from people on dialysis do not transfer to people with early CKD or to healthy kidneys, and fatty liver trials do not transfer to other liver diseases.
The reviews combined different products, amounts and trial lengths. A change in liver enzymes or triglycerides is not the same as preventing liver or kidney failure.

Safety and who should ask a clinician

Kidney and liver conditions can change which medicines and supplements are suitable, so ask a nephrologist, hepatologist or pharmacist first. Labeling for a prescription EPA product advises periodic ALT and AST monitoring in people with hepatic impairment. [7] NCCIH lists mild side effects such as taste changes and stomach upset. [8] Prescription EPA labeling also warns about fish and shellfish allergy and bleeding with blood thinners. [7] See omega-3 cautions in kidney and liver disease, medication interactions and product quality testing.

References

Rinella ME et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology 2023. Read 2026-10-23.
Effects of omega-3 polyunsaturated fatty acid intake in patients with chronic kidney disease: systematic review and meta-analysis of randomized controlled trials. Clin Nutr 2020. Read 2026-10-23.
NIDDK, Treatment for NAFLD & NASH. Read 2026-10-23.
Wu MY et al. Omega-3 fatty acids for dialysis vascular access outcomes in patients with chronic kidney disease. Cochrane Database Syst Rev 2018. Read 2026-10-23.
Omega-3 polyunsaturated fatty acids and nonalcoholic fatty liver disease in adults: a meta-analysis of randomized controlled trials. Clin Nutr 2025. Read 2026-10-23.
Effects of omega-3 polyunsaturated fatty acid supplementation on non-alcoholic fatty liver: a systematic review and meta-analysis. Nutrients 2020. Read 2026-10-23.
US National Library of Medicine, DailyMed prescribing information for a prescription icosapent ethyl (EPA ethyl ester) product. Read 2026-10-23.
NCCIH, Omega-3 Supplements: What You Need To Know. Read 2026-10-23.

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.