When asking how much omega-3 you need, it's just as important to know which type, you're getting, how often you eat oily fish and whether your needs have changed through pregnancy, diet or a particular health condition.
Omega-3 is not one single nutrient with one universal target. A thoughtful approach starts with food, then uses a supplement only where it adds something meaningful to your routine. If the three forms are new to you, our explainer on EPA, DHA and ALA sets out the difference.
The three omega-3 fats worth knowing
The omega-3 family includes alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). They are related, but they are not interchangeable in practice.
ALA is found in plant foods, including flaxseed, chia seeds, walnuts, rapeseed oil and soya. It is an essential fatty acid, meaning it must come from the diet. The body can convert a small amount of ALA into EPA and DHA, although that conversion is limited and varies between individuals.
EPA and DHA are the long-chain omega-3s found most directly in oily fish and marine algae. They have different roles in the body, which is why most supplements provide both rather than just one. EPA and DHA both contribute to normal heart function when consumed at a daily intake of 250mg EPA + DHA. while 250mg DHA contributes to maintenance of normal brain function and vision.
In reality, most fish oil (salmon, sardines, mackerel, trout, herring and pilchards) and algae oil supplements provide a combination, and the total amount of EPA plus DHA is more informative than the headline amount of fish oil. People with fish allergy should check product suitability carefully, and algae-derived products may be an alternative.
How much omega-3 do you need?
For most adults, current UK advice recommends eating at least two portions of fish each week, including one portion of oily fish.
European guidance commonly recognises 250mg per day of combined EPA and DHA as sufficient for maintenance of normal heart function in healthy adults. These figures are useful reference points rather than a reason to pursue the highest possible dose. Your ideal intake depends on what is already on your plate, not simply what is written on a supplement label.
| Situation | A considered omega-3 approach |
|---|---|
| Most healthy adults | Two fish portions weekly, including one portion of oily fish, or a supplement providing around 250mg EPA and DHA daily if fish is rarely eaten. |
| Pregnancy and breastfeeding | Include fish within UK safety guidance and consider whether additional DHA is appropriate with a pharmacist, midwife or clinician. |
| Vegetarian or vegan diets | Prioritise ALA-rich foods and consider an algae oil that states its DHA and EPA content clearly. |
| Raised triglycerides or cardiovascular care | Seek medical advice. Higher-dose omega-3 treatment is not a substitute for clinical assessment or prescribed medication. |
A weekly food pattern is often easier to maintain than trying to achieve an identical intake every day. A serving of grilled salmon one evening and sardines on toast another day can contribute more than a low-strength capsule taken inconsistently.
Start by looking at your diet
Oily fish is a particularly efficient source of EPA and DHA, but it is not the only consideration. Your overall diet matters too: fibre-rich plants, protein, unsaturated fats and a varied intake of micronutrients all support a balanced approach to wellbeing.
If you eat oily fish once or twice a week, a daily omega-3 supplement may be optional. It can still be a matter of preference, particularly if travel, busy working weeks or changing tastes make your food intake unpredictable. If you never eat fish, a supplement is a more straightforward way to obtain preformed DHA and, where included, EPA.
Tinned fish can be an excellent everyday choice provided it is not heavily salted. Sardines, mackerel and salmon are convenient, typically lower in cost than fresh fillets and easy to keep on hand. White fish, such as cod or haddock, provides valuable nutrition but generally contains far less EPA and DHA than oily fish.
Those following a plant-based diet should not assume that flaxseed oil alone delivers the same result as marine omega-3. It remains a useful source of ALA, but an algae-based supplement offers a direct source of DHA and sometimes EPA, without using fish.
Algal oil is produced from marine microalgae such as Schizochytrium - the original source of omega-3 and are eaten by fish. It provides DHA, and sometimes EPA, without using fish. It can also appeal to people following a vegan diet or those looking for a more sustainable source of omega-3. - Our vegan omega range includes algae-derived options
Choosing an omega-3 supplement with precision
A product labelled "1,000mg fish oil" does not necessarily provide 1,000mg of omega-3. The important figure is the amount of EPA and DHA listed on the nutrition panel, which is often much lower than the total fish oil weight. Always turn to the nutrition panel and look for the separate quantities of EPA and DHA per daily serving. This is the figure to compare between products - our guide to choosing an omega-3 supplement goes deeper into reading a label.
For everyday use, a formula supplying at least 250mg or more of combined EPA and DHA can suit people who do not regularly eat oily fish. Concentrated products may provide this amount in one capsule, while standard-strength fish oils can require two or more. Neither format is inherently superior; consistency, tolerance and the actual dose are what matter.
Fish oil is available in capsules and liquids, while algae oil is usually presented in capsules or softgels. A liquid can be helpful for people who dislike swallowing capsules, whereas capsules are discreet and convenient for a handbag or desk drawer. Taking omega-3 with a meal can improve comfort for those prone to fishy aftertaste or indigestion.
Quality should be assessed beyond the dose. Choose a product manufactured to recognised quality standards and with clearly declared EPA and DHA content in each serving. Omega-3 oils are delicate, so follow the label carefully. Some liquids should be refrigerated after opening, and all formats should be kept away from heat and direct light.
Cod liver oil deserves a separate mention. It provides omega-3, but it may also contain significant amounts of vitamins A and D. This can be useful in some circumstances, yet it is not interchangeable with a purified fish oil. Avoid doubling up with other supplements containing vitamin A. Cod liver oil should not be taken alongside other vitamin A-containing supplements or during pregnancy or if you are trying to conceive unless advised by a healthcare professional.
When individual advice matters
Pregnancy and breastfeeding are times to be particularly selective. DHA contributes to normal development of the eyes and brain of the foetus and breastfed infants when taken by the mother, but food safety guidance still applies. Higher-DHA formulas suitable for this stage are grouped in our pregnancy range. Oily fish is valuable, although pregnant women should limit it in line with UK recommendations and avoid fish liver oils because of their vitamin A content.
If you take anticoagulant or antiplatelet medicines, have a bleeding disorder, are preparing for surgery or are under specialist care, speak to a pharmacist, GP or prescribing clinician before starting a higher-dose omega-3 product. Standard dietary quantities are different from therapeutic doses, which should never be self-directed.
People managing high triglyceride levels may encounter products with substantially larger amounts of EPA and DHA. These doses should be treated as part of a clinical plan, not an extension of general wellness supplementation. The cause of raised triglycerides, your medication and your wider cardiovascular risk all need consideration.
For children, the right approach is age-dependent. Fish can be a nutritious part of family meals, but adult capsules and doses are not automatically appropriate. A pharmacist can help identify a format and amount suited to the child's age and diet.
Make the choice easy to sustain
The most refined wellness routine is usually the one that fits naturally into ordinary life. If you enjoy salmon, mackerel or sardines, build them into meals you genuinely look forward to. If fish is absent from your diet, select an EPA and DHA supplement with a clear label, a suitable format and a dose that complements rather than complicates your routine. Our omegas and oils range covers the forms discussed here.
A pharmacist can offer valuable guidance where diet, medicines or life stage make the decision less clear. The aim is not to chase the largest number on a bottle, but to make a well-informed choice you can continue with confidence.