Is Fish Oil Good for Fatty Liver? What the Trials Show
Fish oil lowers triglycerides but has not been shown to treat fatty liver; the AASLD lists omega-3s as lacking liver-specific benefit. Eat the fish instead.
TL;DR
- Fish oil lowers blood triglycerides, but it has not been shown to improve the scarring or inflammation of fatty liver disease. The AASLD lists omega-3s among drugs “not found to have liver-specific benefits,” and the European guideline says nutraceuticals cannot be recommended.
- The trial results on liver fat are mixed: positive in some meta-analyses, null in the most recent one.
- If you take fish oil for high triglycerides your doctor found, there is no liver reason to stop. If you are considering it to treat fatty liver, eating oily fish is the better move.
Fish oil is not a proven treatment for fatty liver. It reliably lowers triglycerides, and some trials show small improvements in liver fat, but the best evidence has found no benefit on the features that matter most for MASLD (metabolic dysfunction-associated steatotic liver disease, formerly NAFLD): inflammation and scarring.
This page is about the supplement. For the food, including salmon, sardines and how to cook them, see is fish good for fatty liver.
What do liver guidelines say about fish oil?
- AASLD (2023): the practice guidance lists “n-3 polyunsaturated fatty acids” among “other available drugs not found to have liver-specific benefits.” For blood fats, it says prescription-grade omega-3 fatty acids or icosapent ethyl, alongside fibrates, can be used for severe high triglycerides to reduce pancreatitis risk, and icosapent ethyl is indicated alongside a statin for people at high cardiovascular risk. So omega-3s have a place in lipid care, not liver care.
- EASL–EASD–EASO (2024): omega-3s are described as having anti-inflammatory and insulin-sensitizing effects, but EPA supplementation did not show histological benefit over placebo in randomized trials. The guideline also states that in adults with MASLD, nutraceuticals “cannot be recommended since there is insufficient evidence of their effectiveness” in reducing liver damage, “nor of their safety.” A newer engineered omega-3, icosabutate, is still being tested.
- NIDDK: advises replacing saturated and trans fats with unsaturated fats, “especially omega-3 fatty acids,” which may reduce your chance of heart disease. That is advice about food fats, not an endorsement of capsules for the liver.
What do the trials show?
The biggest placebo-controlled trial was negative. In the EPE-A trial (Gastroenterology, 2014), 243 adults with MASH at 37 North American sites took placebo, 1,800 mg/day or 2,700 mg/day of EPA ethyl ester for 12 months. About 40%, 37% and 36% of the groups met the primary histology endpoint, no significant difference. EPA had no significant effect on steatosis, inflammation, ballooning or fibrosis scores, or on liver enzymes. The high dose lowered triglycerides (by 6.5 mg/dL versus a 12 mg/dL rise on placebo). There were no treatment-related serious adverse events.
Meta-analyses disagree:
| Meta-analysis | Trials / people | Findings |
|---|---|---|
| Lee et al., Nutrients 2020 | 22 trials, 1,366 | Improved liver fat vs placebo; lowered triglycerides and total cholesterol, raised HDL; small BMI reduction |
| Kim et al., Clinical Nutrition 2025 | 20 trials, 1,615 | Improved GGT and ultrasound-graded steatosis; no significant effect on AST, ALT, MRS or MRI-PDFF liver fat, liver stiffness or histology; more adverse events than control |
Why the difference? The 2025 review covered trials through November 2024 and analyzed each measurement method separately. The ultrasound finding rested on a limited number of studies and a less precise method, while the MRI and MRS fat measurements, which are more precise, showed no significant effect. The 2025 authors also noted heavy variation between trials and called for better-designed ones.
My reading: fish oil might trim liver fat a little in some people, but nothing shows it reverses inflammation or fibrosis, which are what raise the risk of cirrhosis. For how those are improved, see how to reverse fatty liver.
What are the downsides of fish oil supplements?
Most people tolerate fish oil, but it is not risk-free:
- Everyday side effects. NIH lists an unpleasant taste, bad breath, heartburn, nausea, stomach discomfort, diarrhea and headache, usually mild.
- Blood thinners. Fish oil has mild antiplatelet effects at high doses and might prolong clotting time when taken with warfarin. NIH says people on warfarin or similar anticoagulants should discuss omega-3s with their provider, and labels of prescription omega-3 products advise periodic INR checks. Tell your doctor and pharmacist, including before surgery.
- Atrial fibrillation. A 2021 meta-analysis in Circulation of 7 large trials (81,210 people, average follow-up 4.9 years) found marine omega-3 supplements were linked to a higher risk of atrial fibrillation (hazard ratio 1.25). The hazard ratio was 1.49 in trials testing more than 1 g a day and 1.12 at 1 g a day or less. These were people in cardiovascular trials, not fatty liver studies.
- Vitamin A in some products. NIH notes that cod liver oil supplements provide vitamin A and vitamin D as well as omega-3s. Too much preformed vitamin A can itself injure the liver, so check the label and ask your doctor before using one if you have a liver condition.
- Quality and dose. The label’s EPA and DHA amounts are what count, not “1,000 mg fish oil.” Supplements aren’t pre-approved by regulators, so choose products with independent testing.
Fish oil in the doses used in liver trials is not trivial: the EPA trial gave 1.8 to 2.7 g a day, so compare that with the EPA and DHA per capsule on your label. NIH reports that the FDA recommends not exceeding 3 g a day of EPA and DHA combined, with up to 2 g a day from supplements, and some trial doses exceed that.
Is it better to eat fish or take fish oil?
Eating fish is better supported, for several reasons:
- Both liver guidelines recommend a Mediterranean-style diet, which includes fish and seafood. It is the pattern with the best liver evidence, not omega-3 capsules.
- Fish brings protein, and it displaces red and processed meat, which are more consistently linked to fatty liver. See is red meat bad for fatty liver.
- Oily fish gives meaningful omega-3s: per 3 ounces cooked, about 1.8 g EPA and DHA in farmed Atlantic salmon, 1.7 g in herring and 1.0 g in Atlantic mackerel, and 1.2 g in canned sardines (NIH Office of Dietary Supplements, from USDA data). See are sardines good for fatty liver and is tuna good for fatty liver.
Even so, a population-level link between fish and fatty liver is mixed, so fish is a good choice as part of the pattern, not a cure. If you do not eat fish for dietary or ethical reasons, discuss plant-based sources and algae-based DHA with a dietitian. I did not find liver trials on those.
Who might still take fish oil?
There are good reasons to use it, just not as a liver treatment:
- High triglycerides. Prescription omega-3 products are used for high triglycerides. Fatty liver and high triglycerides often go together. Your doctor decides the product and dose.
- Heart disease risk. Icosapent ethyl, a purified EPA drug, is used with statins in high-risk people, as the AASLD guidance notes.
- A recommendation from your own doctor. Keep taking it as directed, and mention it at appointments.
For most people with fatty liver and normal triglycerides, the money is better spent on fish, vegetables and olive oil. If you log meals in an app like Liverly, you can see how often oily fish actually lands on your plate.
The Bottom Line
Fish oil is not a proven treatment for fatty liver. It lowers triglycerides, some trials show modest liver-fat improvements, and the biggest placebo-controlled trial found no benefit on liver inflammation or scarring. The AASLD says omega-3s have no liver-specific benefit, and the European guideline does not recommend nutraceuticals for MASLD.
If you want the omega-3s, eat oily fish twice a week and bake or grill it. If your doctor has prescribed fish oil for triglycerides, keep taking it and do not add more on your own. Either way, the changes with the strongest evidence are weight loss, a Mediterranean-style diet and regular activity.
Sources
- Rinella ME, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology. 2023.
- EASL–EASD–EASO Clinical Practice Guidelines on the management of MASLD. J Hepatol. 2024.
- Sanyal AJ, et al. No significant effects of ethyl-eicosapentanoic acid on histologic features of nonalcoholic steatohepatitis in a phase 2 trial. Gastroenterology. 2014.
- Lee CH, et al. Effects of omega-3 polyunsaturated fatty acid supplementation on non-alcoholic fatty liver: a systematic review and meta-analysis. Nutrients. 2020.
- Kim SJ, et al. Omega-3 polyunsaturated fatty acids and nonalcoholic fatty liver disease in adults: a meta-analysis of randomized controlled trials. Clin Nutr. 2025.
- Gencer B, et al. Effect of long-term marine omega-3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials of cardiovascular outcomes. Circulation. 2021.
- NIH Office of Dietary Supplements: Omega-3 fatty acids, fact sheet for consumers.
- NIDDK: Eating, diet and nutrition for NAFLD and NASH.
This article is for informational purposes only and is not medical advice. Talk to your doctor or hepatologist about your specific situation.
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Frequently Asked Questions
Does fish oil reduce liver fat?
Possibly a little, but the evidence is inconsistent. A 2020 meta-analysis of 22 trials with 1,366 people found omega-3 supplements improved liver fat compared with placebo. A 2025 meta-analysis of 20 trials with 1,615 people found no significant effect on liver fat measured by MRI or MRS, stiffness or biopsy results, though it did find improvements in GGT and in ultrasound-graded steatosis. Larger, better trials are needed.
Can fish oil heal liver scarring or MASH?
There is no evidence that it does. In the largest placebo-controlled trial, 243 adults with MASH took 1,800 or 2,700 mg a day of EPA ethyl ester or placebo for 12 months. About 40%, 37% and 36% met the primary histology goal, which was not a significant difference, and there was no significant effect on fibrosis scores. The AASLD says omega-3s have not been found to have liver-specific benefits.
Is fish oil good for triglycerides in fatty liver?
Yes, that is the clearest benefit. Meta-analyses find omega-3 supplements lower triglycerides, and the AASLD guidance mentions prescription-grade omega-3s and icosapent ethyl for people with high or severely high triglycerides. In the EPA trial, the high dose cut triglycerides by about 6.5 mg/dL while the placebo group rose by 12. That is a heart and lipid benefit, so your doctor decides on dose and product.
Are there risks of taking fish oil?
Usually mild: NIH lists an unpleasant taste, bad breath, heartburn, nausea and loose stools. Two bigger cautions: fish oil may affect clotting in people taking blood thinners like warfarin, and a 2021 meta-analysis of 7 trials with 81,210 people linked marine omega-3 supplements to a higher risk of atrial fibrillation, with a higher risk above 1 g a day. Talk to your doctor before starting.
Is it better to eat fish or take fish oil for fatty liver?
Eating fish is the better-supported choice. Both major liver guidelines point to the Mediterranean diet, which includes fish and seafood, and fish replaces red and processed meat on the plate. Supplements have not shown the same liver benefit. Two servings a week of oily fish such as salmon, sardines or trout gives you omega-3s plus protein, without the pill. Cook it baked, grilled or poached.