Summary
- What are the benefits of fish oil? Taking a supplement with EPA and DHA from fish oil (or other source, such as krill oil or algae) offers a wide range of potential benefits for mental health, treating inflammatory disease, maintaining muscle, and even cancer prevention (see What It Does). As far as cardiovascular and cognitive (and memory) benefits, eating fish at least twice each week may do you more good than taking a fish oil supplement, although, if you eat fish, be aware that some types can be high in mercury -- see Getting EPA and DHA from Food).
- How much fish oil should you take? Different amounts of EPA and DHA have been used for different purposes. A general daily dose is about 300 to 500 mg of EPA and DHA, while some treatments (such as for high triglycerides) involve doses as high as 4,000 mg per day (see What to Consider When Using - Dosage). Focus on the amounts of EPA and DHA in a product rather than the amount of total oil, since the concentration of EPA and DHA in oils ranges from about 33% to 85% and, for some uses, you may want more EPA or more DHA (see the comparison graph and second column of the Results table below for amounts of EPA and DHA and concentration levels, as well as amounts of "the other omega-3" DPA, and omega-7 fatty acids).
- When is the best time to take fish oil? Taking fish oil with a meal containing other fats may improve absorption. If you need a high daily dose, dividing the dose over the course of the day may reduce any unpleasant aftertaste and "fishy burps." Enteric-coated capsules can also reduce these effects but may possibly reduce absorption.
- What is the best form of fish oil? Fish oil in supplements is generally first processed to purify it. This often involves modifying its chemical form. While all forms can help raise EPA and DHA levels and do so equally well if taken with a high-fat meal, if not taken with a high-fat meal the "re-esterified triglyceride" form may be the best absorbed, with up to 76% greater absorption than from the more common "ethyl ester" (or just "triglyceride") form (see ConsumerTips -- Forms of Fish Oil). You can check the form of each product in the 2nd column of the table below.
- Which fish, krill, and algal oils are the best? Choose a supplement listed as Approved by ConsumerLab.com in the table below, because not all supplements contain their listed amounts of omega-3 fatty acids, and some may be rancid or contaminated. If you need a high dose, it may be more convenient to pick one with a higher concentration (see the 4th column of the column of the Results table) so that you can take fewer and/or smaller pills or other units. Compare prices to save money (see comparison graph and 5th column of the Results table). To save time, see our Top Picks — these are Approved products that offer exceptional value compared to other products in their categories, including fish oils in softgels, enteric-coated capsules, bottled liquids, as a prenatal supplement, for children, and for pets, as well as our Top Picks for krill oil and vegetarian algal oil (from algae). We also have Top Picks for getting DPA (the "other omega-3") and omega-7 fatty acids. You'll see that you can get high-quality supplements for just pennies a day. Be mindful of added ingredients, like vitamins, so you don't unintentionally exceed tolerable intake limits for these.
- How should fish oil be stored? Store oils out of heat and light — refrigeration is a good idea, particularly for opened bottles of liquid fish oil (see Keep It Fresh).
- Which fish oil supplements are most like prescription omega-3 drugs? Some supplements have similarly high amounts and concentrations of EPA and DHA as found in prescription omega-3 drugs like Vascepa and Lovaza, but at lower cost than these brand-name medications. See how they compare.
- What are fish oil's side effects? Is fish oil safe? Although generally safe, high amounts of EPA and DHA may suppress the immune system and increase the risk of abnormal heart rhythm (atrial fibrillation). It's best to limit daily intake of EPA and DHA from supplements to no more than 2 grams, unless medically indicated. Fish oil may also thin the blood and slightly lower blood pressure. See Concerns and Cautions for more information. As mentioned, take fish oil with food to reduce fishy burps, a common side effect.
