Is There A Best Time To Take That Fish Oil Supplement? Experts Weigh In

Fish oil is one of the most popular supplements1 out there—and considering it provides omega-3s EPA and DHA, two critical fatty acids that most Americans (as in more than 90%2) don't eat enough of, that's for good reason.

As with any supplement, though, reaping the maximum benefits means taking it properly. And while you probably already know that it's important to take certain vitamins (like vitamin D!) with food that contains fat to promote optimal absorption, you might not know that there's actually an ideal time and way to take your fish oil, too. Surprise; there is!

Before diving into when you should take fish oil, let's talk about why taking it can be such a valuable move for your health and well-being in a variety of ways.

Despite their long, long list of helpful properties, though, most people don't get enough omega-3s. "If you aren't regularly eating cold-water fish or flax or walnuts, you may be deficient and could benefit from the use of a supplement," says Nicole Avena, Ph.D., assistant professor of neuroscience at Mount Sinai Medical School and visiting professor of health psychology at Princeton University.

Another factor that makes supplementing even more appealing: Upping your intake of omega-3s can help balance the important ratio of omega-3 to omega-6 fatty acids in your diet. While omega-6 fatty acids, another type of polyunsaturated fat primarily found in vegetable oils (e.g., canola and soybean oils), nuts, and seeds, aren't inherently bad, they can contribute to inflammatory pathways when eaten in excess6—which is very much the case in many Western diets.

"Modern agriculture produces vast amounts of omega-6s, and as a result, we eat much more of this fat category than our ancestors (or even our grandparents) did," says nutritionist Colette Heimowitz, M.Sc., nutrition communication and education for Simply Good Foods. On average, Americans eat about 10 to 20 times as many omega-6 fatty acids as omega-3s,7 thanks in large part to overconsumption of processed foods, which are often high in vegetable oils and severely lacking in omega-3s. (Turns out the ideal ratio is 2:18.)

When it comes to fish oil, the specific time of day doesn't seem to matter as much as the types of food you pair your supplement with. "The omega-3 fatty acids in fish oil have been shown to be better absorbed when taken with a fat-containing meal rather than on an empty stomach,"* says Heimowitz.

Avena agrees: "This can increase the bioavailability of the omega-3s, meaning that you are more likely to absorb them."*

It's worth noting, though, that the form of fish oil you take can also influence your ability to absorb those omega-3s—and how important it is that you pop your supplement alongside a meal.* The omega-3s in fish oil supplements come in two major forms: triglycerides (a more natural form, like the kind you find in actual fish) and ethyl esters (a further processed form that may cost you more in the long run).

Here's the deal on these two options: According to a 2020 randomized controlled clinical trial published in the European Journal of Clinical Nutrition9, absorption of triglyceride forms is three to five times higher than that of ethyl esters. Blood levels of EPA and DHA also remain higher 24 hours after taking triglycerides compared to ethyl esters.*

The researchers of another study10 (that's older but still relevant), meanwhile, looked at the difference that high-fat meals have on absorption rates of triglyceride versus ethyl ester forms of fish oil. They found that without the high-fat meal, the absorption rate of ethyl esters hovered around 20%. With the fatty meal, absorption increased to 60%. For triglycerides, meanwhile, absorption was much higher, at 69% without a high-fat meal and 90% with one.

All of this suggests that taking your fish oil supplement with (or around the time of) a fat-containing snack or meal is always a good idea, but that there's much more at stake when it comes to absorption if you're popping an ethyl ester form supplement over a triglyceride one.*

How can you tell which form a product contains, though? Most companies that feature the native form of fish oil/fat (i.e., triglyceride form) of omega-3s in their fish oil are proud of it—and call it out right on the label. Take a look at the Supplement Facts panel on a bottle of mbg's omega-3 potency+, for example, and you'll see "EPA (eicosapentaenoic acid triglyceride)" and "DHA (docosahexaenoic acid triglyceride)" specifically highlighted beneath the breakdown of "total omega-3s" per serving.

Given all of this, there's no bad time to take fish oil, per se—but there is a factor or two you'll want to think about.

If you've ever taken a fish oil supplement (or at least considered it), you've probably heard about a not-so-pleasant potential side effect known as "fish burps." Some people find that taking their supplement on an empty stomach makes fishy-smelling belches worse.