Omega-3s can reduce your risk of heart disease and cancer, ease your aches and pains,
and improve your mood. But as the products on the shelf multiply, choosing an omega-3 supplement has become downright confusing. Use this glossary to guide your purchase.

EPA and DHA.

These acronyms stand for eicosapentaenoic acid and docosahexaenoic acid. You need both of these omega-3 essential fatty acids: EPA has stronger anti-inflammatory benefits (read: heart health, joints), while DHA seems to improve brain development and memory. They work together to promote good moods, but EPA seems more helpful for depression. Check labels for about a 2:1 ratio of EPA and DHA per serving—as opposed to just “fish oil,” which can also contain saturated fat.

Fish sources.

Except for salmon and cod-liver oil, most omega-3 supplements come from small species such as anchovies and sardines. Distillation processes make fish oil supplements largely free of heavy metals and contaminants—not the case with many fish we eat. (Tests by Consumer Reports recently identified a few products with PCB levels that may have required warning labels under California’s Proposition 65.)

"Whole" omegas.

This term, along with full-spectrum and minimally processed, can sometimes be as slippery as, yep, a fish. All omega-3s are extracted via a distillation process, so take the minimally processed claim with a grain of salt. Some “whole” products contain blends of ingredients you probably don’t need, such as omega-9s (plentiful in olive oil). Small amounts of omega-5, -7, and -8 may be just window dressing—you’d need far more to see benefits. Some products also contain added astaxanthin, a reddish antioxidant found in certain algae and salmon that may have antiaging effects.


Phospholipids are found in all cell membranes in the body; the omega-3 fats bound to them help keep the membranes supple and may have an advantage when it comes to uptake by the body. Krill and a few fish-oil products (Jarrow PhosphOmega, EuroPharma Vectomega) are phospholipids. The more common triglyceride form—found naturally in fatty fish and flaxseed—must be digested before it enters the bloodstream, but research shows  triglycerides just as effectively treat most conditions, with one exception: people with mood issues, because phospholipids have additional brain benefits.


Omega-3 supplements sourced from these tiny crustaceans have much less EPA and DHA than fish oil, but proponents say that because krill’s phospolipid form is better absorbed, they offer similar benefits. There’s still very little human clinical research on krill supplements, so it’s not yet clear they’re better than other omega-3 sources, and they can be more expensive. Krill sustainability also remains hotly debated. Producers and an international regulating body say current krill harvests are sustainable, but some environ-mentalists contend they may reduce a key food source for ocean species, including endangered penguins and whales.

Vegetarian or vegan omega-3s.

Plant oils, such as those from flaxseed and chia, contain alpha-linolenic acid (ALA), the “parent molecule” of EPA and DHA. Although ALA has some health benefits, most people’s bodies convert very little of it to more research-backed EPA or DHA. Vegetarians seem to have a higher ALA conversion rate.    

Algae—where fish get their EPA and DHA—is a rising plant source for omega-3s. Sustainably farmed, free of ocean contaminants, and vegan, algal oil supplements now offer DHA as well as both EPA and DHA. Are they as effective as fish oil? Aside from doses, the DHA and EPA are identical to those in fish oils (and krill).

Savvy shopper secrets 

  • Buy reputable brands from a trusted retailer who sells fresh products.
  • Check labels for third-party certifications, such as the IFOS-5 seal.
  • Once home, refrigerate or freeze.
  • Take with food that has some fat to stimulate bile secretion, which enhances fat absorption.
  • If you get fish burps, take pills near bedtime or try enteric-coated capsules.