Omega-3 supplements: EPA, DHA, choice and safety

ALA is an essential fatty acid. The body can convert some of it into EPA and then DHA, but conversion is limited. ALA therefore matters in the diet, yet it is not a simple equivalent of directly supplied EPA or DHA.[1]

A product labelled “1,000 mg fish oil” does not necessarily provide 1,000 mg of EPA+DHA. Formulations vary widely; the lines listing both fatty acids allow a useful comparison.[1]

Food remains the first lever. Oily fish provide EPA and DHA, while plant sources such as walnuts and some oils mainly provide ALA. Algal oils are a vegetarian source of DHA, with variable formulations.[1][2]

High omega-3 doses may interact with medicines that affect clotting; seek advice before using them if you take an anticoagulant or antiplatelet drug. Also mention the supplement before surgery and in case of chronic disease or pregnancy.[1]

EFSA did not establish a tolerable upper intake level, but concluded that supplemental EPA+DHA up to 5 g/day raised no safety concerns for adults in its assessment. This is not a target dose or personal advice.[3]

1. 01Check whether your diet already meets your needs and why you are considering a supplement.
2. 02Read EPA and DHA separately, using the actual daily serving.
3. 03Compare the source and tolerance; cod-liver oil and fish oil are not the same.
4. 04Ask for advice if you take medication, are pregnant or breastfeeding, or have a chronic condition.