Omega-3 fatty acids

Is algae oil as good as fish oil?

Updated 9 Nov 2026

Short answer

For raising blood DHA, studies suggest so. In a 2-week trial in 32 adults, 600 mg of DHA a day from algae oil capsules raised blood DHA as much as the same amount from cooked salmon.[1] A 2012 review of 11 trials found that DHA from algae oil lowered triglycerides.[2] Most algae oils give mainly DHA, about 100 to 300 mg, and only some add EPA.[3]

Where the omega-3 in fish comes from

Microalgae make EPA and DHA. Fish take them in through the food chain and store them.[3] Algae oil supplements are a vegetarian source of DHA, and some also contain EPA.[4] They usually contain the omega-3 as triglycerides, the form found naturally in fish oil.[3] Fish oil has both EPA and DHA: a typical 1000 mg capsule holds 180 mg of EPA and 120 mg of DHA.[3] Krill oil carries its omega-3 mostly as phospholipids.[3]

What trials found

  • Blood levels. In a randomized trial, 32 healthy adults aged 20 to 65 got 600 mg of DHA a day for 2 weeks, from algae oil capsules or from cooked salmon. DHA rose by about 80% in plasma and by about 25% in red blood cells in both groups.[1] The NIH calls this a small study.[3]
  • Omega-3 index. A 2022 review of 13 trials found that algae oil raised the omega-3 index in every study. High doses of flaxseed oil or echium seed oil did not.[5] An earlier review found the same. In 3 studies, algae oil raised DHA in blood. In 7 studies, ALA from nut and seed oils was not turned into DHA at all.[6]
  • Blood fats. A 2012 review of 11 trials with 485 healthy people gave a median of 1.68 g of DHA a day from algae oil. Triglycerides fell by 0.20 mmol/L. HDL cholesterol rose by 0.07 mmol/L and LDL cholesterol by 0.23 mmol/L.[2]
  • Breast milk. In mothers who gave birth before 29 weeks, DHA-rich algae oil raised DHA in breast milk from 0.34% to 0.95% of its fatty acids.[7]

DHA and LDL cholesterol

Most algae oils provide mainly DHA.[3] A 2011 review found that DHA alone raised LDL cholesterol compared with placebo, while EPA alone did not.[8] EFSA found that DHA at 2 to 4 g a day raised LDL cholesterol by about 3%, which may not affect heart risk.[9]

What is less known

The trials in the 2012 review measured blood fats in people without coronary heart disease, not heart attacks or strokes.[2] None of the large heart trials described by the NIH used algae oil. They used fish oil or other omega-3 products, including prescription forms.[3]

Reading the label

Omega-3 products differ a lot, so the label is the place to check which omega-3 fats a product has and how much of each.[3] Pregnant women who eat a vegetarian or vegan diet are advised to ask a health care provider whether they need EPA and DHA supplements.[3]

Sources (9)

  1. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid. Arterburn LM, Oken HA, Bailey Hall E, Hamersley J, Kuratko CN, Hoffman JP J Am Diet Assoc, 2008. PMID 18589030
  2. 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. Bernstein AM, Ding EL, Willett WC, Rimm EB J Nutr, 2012. PMID 22113870
  3. Omega-3 Fatty Acids: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  4. Omega-3 Supplements: What You Need To Know. NIH National Center for Complementary and Integrative Health, 2024. www.nccih.nih.gov
  5. Bioavailability and conversion of plant based sources of omega-3 fatty acids - a scoping review to update supplementation options for vegetarians and vegans. Lane KE, Wilson M, Hellon TG, Davies IG Crit Rev Food Sci Nutr, 2022. PMID 33576691
  6. Bioavailability and potential uses of vegetarian sources of omega-3 fatty acids: a review of the literature. Lane K, Derbyshire E, Li W, Brennan C Crit Rev Food Sci Nutr, 2014. PMID 24261532
  7. Docosahexaenoic acid-rich algae oil supplementation on breast milk fatty acid profile of mothers who delivered prematurely: a randomized clinical trial. Fougère H, Bilodeau JF, Lavoie PM, Mohamed I, Rudkowska I, Pronovost E, et al. Sci Rep, 2021. PMID 34728723
  8. Effects of eicosapentaenoic acid versus docosahexaenoic acid on serum lipids: a systematic review and meta-analysis. Wei MY, Jacobson TA Curr Atheroscler Rep, 2011. PMID 21975919
  9. Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). European Food Safety Authority, 2012. efsa.onlinelibrary.wiley.com

More about omega-3 fatty acids

What are omega-3 fatty acids?What is the difference between ALA, EPA and DHA?What are omega-3 fatty acids used for?Which foods are high in omega-3?Are omega-3 supplements safe?Does plant omega-3 (ALA) protect the heart?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.