Fish oilWhat is fish oil?
Updated 4 Nov 2026
Short answer
Fish oil is a dietary supplement made from the fat of fish. It contains EPA and DHA, two long-chain omega-3 fats.[1] Fish do not make these fats themselves: microalgae make them, and fish collect them through the food chain.[1]
A typical 1000 mg capsule holds about 180 mg of EPA and 120 mg of DHA.[1] Related products are cod liver oil, which also has vitamins A and D, krill oil and algal oil, the vegetarian source.[2] Cold-water fatty fish such as salmon, mackerel, herring and sardines are rich food sources.[1]
Sources (2)
- Omega-3 Fatty Acids: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
- Omega-3 Supplements: What You Need To Know. NIH National Center for Complementary and Integrative Health, 2024. www.nccih.nih.gov
More about fish oil
Does fish oil reduce inflammation?How much EPA and DHA is in a fish oil capsule?Is eating fish better than taking fish oil?What is fish oil used for?Should fish oil be taken with food?Does fish oil prevent heart attacks?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.