# Fish oil, algal oil, krill and cod liver oil: which is which > Omega-3 capsules get their omega-3 from fish, krill, cod liver or algae. The source tells you whether a pack fits what you eat. - Canonical: https://kilocare.in/learn/kinds-of-omega-3-supplement - Publisher: KiloCare (https://kilocare.in) - Written by: KiloCare Team - Last updated: 2026-10-23 - Citations: numbers in square brackets refer to Sources at the end; a page or table follows the number where given. ![Three different unlabelled containers, an amber bottle, a cream jar and a dropper bottle, on a pale oak shelf.](https://kilocare.in/images/learn/ill-kinds-of-omega-3-supplement.webp) **In short** - Fish oil, krill oil and cod liver oil carry EPA and DHA from the sea. Cod liver oil also gives vitamins A and D. - Algal oil carries DHA, and some also carry EPA. It is a vegetarian source. - Flaxseed oil gives plant omega-3 (ALA), not EPA and DHA. ## The oils side by side **At a glance** | | Omega-3 it carries | What sets it apart | |---|---|---| | Fish oil | EPA and DHA | The amount in a capsule varies widely, so read the label | | Algal oil | DHA, and in some EPA | A vegetarian source. Check the shell for gelatin. | | Krill oil | EPA and DHA | Mostly in a form called phospholipids | | Cod liver oil | EPA and DHA | Also gives vitamin A and vitamin D. If you are pregnant, ask your doctor first. | | Flaxseed oil | ALA, the plant omega-3 | A food oil. The body turns only a small share into EPA and DHA. | ## Fish oil Fish oil carries EPA and DHA, which fish take in from algae in the sea's food chain.[1, Introduction] The NIH says a typical fish oil supplement gives about 1,000 mg of fish oil, with 180 mg EPA and 120 mg DHA. Amounts vary widely.[1, Sources of omega-3s, Dietary supplements] Our article on [omega-3 safety](https://kilocare.in/learn/omega-3-safety) covers mercury and capsules. ## Algal oil ICMR-NIN, India's National Institute of Nutrition, first advises people who eat no fish to eat more plant omega-3 (ALA).[2, Printed p. 115 (PDF p. 127)] Its tables also list algal oil-based DHA products as a vegetarian source, and say to check the label for the amount.[2, Table 6.6, printed p. 116 (PDF p. 128)] The NIH (US National Institutes of Health) says algal oil capsules usually give about 100 to 300 mg of DHA. In one small study, the body took up DHA from algal oil just as well as DHA from cooked salmon.[1, Sources of omega-3s, Dietary supplements] To check for gelatin, read the ingredients on the back of the pack. Our article on [how to read an omega-3 label](https://kilocare.in/learn/how-to-read-an-omega-3-label) explains the other lines on a pack. ## Krill oil The NIH reports that some studies found krill oil's phospholipids were taken up somewhat better than the omega-3s in fish oil. Others did not.[1, Sources of omega-3s, Dietary supplements] ## Cod liver oil Cod liver oil also gives vitamin A and vitamin D.[1, Sources of omega-3s, Dietary supplements] If you are pregnant, ask your doctor before you choose it. ## Flaxseed oil, a food oil with ALA Flaxseed oil, also called linseed oil or alsi oil, comes from a seed. The NIH fact sheet lists it with foods that give ALA, the plant omega-3, at 7.26 g in 1 tablespoon.[1, Sources of omega-3s, Food, Table 2] Flaxseed oil gives ALA, not EPA and DHA. The body turns only a small share of ALA into EPA and DHA.[1, Introduction] Our article on [what omega-3 is](https://kilocare.in/learn/what-is-omega-3) explains why. ## The form on the label Some labels name the chemical form of the oil, such as triglyceride or ethyl ester. Here triglyceride means the oil's form, not the blood fat of the same name. The NIH says triglyceride forms are absorbed somewhat better than ethyl esters, but every form raises the EPA and DHA in your blood.[1, Sources of omega-3s, Dietary supplements] A 2018 review says this ranking does not always hold in practice.[3, Section 3.2, Chemical binding] So read the milligrams of EPA and DHA first. Our [omega-3 guide](https://kilocare.in/pharmacy/guides/omega-3-explained) covers how to choose a pack. *Ask your doctor before you take an omega-3 supplement if you take a blood thinner or any medicine regularly, are pregnant or breastfeeding, or are buying it for a child.* *If you have a fish or shellfish allergy, ask your doctor before you take fish or krill oil.* *Do not take more than the pack says.* > **Medical disclaimer:** This article is general information. It does not replace advice from your doctor about your own health. Prescription required. Consult your doctor. Results may vary. ## Frequently asked questions **I do not eat fish. How do I get EPA and DHA?** Start with more plant omega-3 (ALA) from food, as ICMR-NIN advises. The body turns only a small share of ALA into EPA and DHA. Algal oils carry DHA, and some also carry EPA. Check the label for the amount, and check whether the shell lists gelatin. **Is algal oil vegetarian?** ICMR-NIN names marine microalgae, the source of algal oil, as a vegetarian source of long-chain omega-3, the kind in fish. Read the ingredients to check what the capsule shell is made of. **Is krill oil absorbed better than fish oil?** The evidence is mixed. The NIH reports that some studies found krill oil's omega-3s were taken up somewhat better than those in fish oil, and others did not. ## Sources 1. National Institutes of Health, Office of Dietary Supplements. Omega-3 fatty acids: fact sheet for health professionals [Internet]. National Institutes of Health; 2025 Aug 22 [cited 2026 Oct 23]. Available from: https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/ 2. ICMR-National Institute of Nutrition. Nutrient requirements for Indians: recommended dietary allowances and estimated average requirements, 2020. A report of the expert group. Hyderabad: ICMR-NIN; 2020. Updated 2024. Available from: https://www.nin.res.in/RDA_Full_Report_2024.html 3. Cholewski M, Tomczykowa M, Tomczyk M. A comprehensive review of chemistry, sources and bioavailability of omega-3 fatty acids. Nutrients. 2018;10(11):1662. doi:10.3390/nu10111662. PMID: 30400360. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6267444/ --- To talk to a KiloCare doctor about weight care in India, start at https://kilocare.in/onboarding.