Fish oil softgels: what the label really tells you
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- Standard 1,000 mg fish oil softgels. Best for: Adults who eat little fish and want a basic omega-3 supplement. See options on Amazon
- Triglyceride-form fish oil softgels. Best for: Adults who want a form NIH describes as somewhat better absorbed. See options on Amazon
- Enteric-coated fish oil softgels. Best for: People bothered by the taste of fish oil. See options on Amazon
Fish oil vs EPA and DHA
Fish oil is the whole oil; EPA and DHA are the long-chain omega-3s in it that most research focuses on. NIH says a typical fish oil supplement provides about 1,000 mg of fish oil containing 180 mg EPA and 120 mg DHA, but doses vary widely.
| Label line | What it means |
|---|---|
| Fish oil 1,000 mg | Total oil, not omega-3s |
| EPA 180 mg | One long-chain omega-3 |
| DHA 120 mg | The other main omega-3 |
| Total EPA plus DHA 300 mg | The figure to compare between products |
Higher-concentration products put more EPA and DHA in each softgel; see our triple-strength fish oil guide.
What fish oil can and cannot do
NIH describes a 2020 Cochrane review of 86 trials with 162,796 people: long-chain omega-3s at 0.5 g to more than 5 g a day lowered triglycerides by about 15% and slightly reduced cardiovascular deaths and coronary heart disease events, but did not reduce overall deaths, stroke or heart rhythm problems.
NCCIH notes that for some conditions the evidence for eating seafood is stronger than for omega-3 supplements. Fish oil is not a substitute for prescribed heart care.
Forms: ethyl ester vs triglyceride
NIH lists several forms of omega-3s in supplements: natural triglycerides, free fatty acids, ethyl esters, re-esterified triglycerides and phospholipids. It says re-esterified triglycerides, natural triglycerides and free fatty acids have somewhat higher bioavailability than ethyl esters, but all forms significantly raise blood EPA and DHA.
NIH also notes omega-3 supplements have not been found to contain methyl mercury, because it is removed during processing.
Side effects and who should check first
NCCIH and NIH describe side effects as usually mild: unpleasant taste, bad breath, bad-smelling sweat, heartburn, nausea, stomach discomfort, diarrhea and headache.
- Blood thinners: fish oil can have antiplatelet effects at high doses and might prolong clotting time with warfarin, though most research found 3 to 6 g a day did not significantly change anticoagulant status. Talk to your doctor.
- High doses: NIH reports that 4 g a day for several years slightly raised the risk of atrial fibrillation in people with or at high risk of heart disease.
- Upper bound: FDA has concluded supplements providing up to 5 g a day of EPA and DHA are safe when used as recommended.
- Cod liver oil: NCCIH notes it also contains vitamins A and D, which can be harmful in excess.
Can you chew fish oil softgels, and how to store them
Most softgels are meant to be swallowed whole; follow the label. Some are enteric coated: for example, NOW Ultra Omega-3 lists an enteric coating on its softgel, which supplies 500 mg EPA and 250 mg DHA, taken 1 to 2 times daily with food. Chewing or breaking a coated softgel defeats the coating. If you prefer chewing, look for chewables or gummies made for it; see our omega-3 gummies guide.
Store softgels as the label directs; the NOW label says to store in a cool, dry place after opening.
How to choose fish oil softgels
- Compare EPA plus DHA per softgel, not total fish oil.
- Count softgels per serving before comparing products.
- Choose a form: triglyceride forms absorb somewhat better, but all forms raise levels.
- Vegetarian? Algal oil is an alternative; see our algae omega-3 guide.
- Look for a verifiable quality mark such as USP or NSF. FDA does not approve supplements before sale.
What to look for when you buy
Standard 1,000 mg fish oil softgels
Best for: Adults who eat little fish and want a basic omega-3 supplement
A typical 1,000 mg softgel gives about 300 mg of EPA plus DHA, per NIH. Check the exact EPA and DHA on the label.
Watch out: The front-label 1,000 mg is total oil. Talk to your doctor if you take a blood thinner.
See options on AmazonTriglyceride-form fish oil softgels
Best for: Adults who want a form NIH describes as somewhat better absorbed
NIH says natural and re-esterified triglycerides have somewhat higher bioavailability than ethyl esters.
Watch out: All forms raise EPA and DHA; the form matters less than the total omega-3 amount.
See options on AmazonEnteric-coated fish oil softgels
Best for: People bothered by the taste of fish oil
Unpleasant taste and bad breath are common omega-3 side effects, and some makers add an enteric coating to the softgel. Compare EPA and DHA per softgel as with any product.
Watch out: Swallow whole; do not chew or cut coated softgels.
See options on AmazonQuestions people ask
- What is fish oil good for?
- It supplies EPA and DHA. In a large Cochrane review, omega-3s lowered triglycerides by about 15% and slightly reduced some heart outcomes, but not overall deaths or strokes.
- Can you chew fish oil softgels?
- Follow the label. Most are designed to be swallowed, and enteric-coated softgels should not be chewed. Choose chewables or gummies if you prefer chewing.
- How much fish oil should I take?
- There is no set EPA and DHA requirement for adults. FDA considers up to 5 g a day of EPA and DHA from supplements safe when used as recommended; ask your doctor about higher amounts.
- Does fish oil contain mercury?
- NIH says omega-3 supplements have not been found to contain methyl mercury, because it is removed during processing.
Sources
- Omega-3 Fatty Acids: Fact Sheet for Health Professionals (ods.od.nih.gov), NIH Office of Dietary Supplements
- Omega-3 Supplements: What You Need To Know (nccih.nih.gov), National Center for Complementary and Integrative Health
- Ultra Omega-3 Fish Oil Softgels (www.nowfoods.com/products/supplements/ultra-omega-3-fish-oil-bovine-gelatin-softgels), NOW Foods