Best fish oil supplements (2026): Momentous, Nordic Naturals and Klean Athlete by cost per gram of EPA and DHA

Which fish oil should you buy?

Choose Momentous Omega-3 if you want the most EPA and DHA for the money in a fish oil NSF lists. Two softgels give 800 mg EPA and 800 mg DHA, 1,600 mg together, and a 60-softgel bottle is $39.99^{1, 2}. That’s about $0.83 per gram of EPA plus DHA and $486.55 a year at the label dose^{1, 2}. NSF lists it for all lots^{3, 4}. The catch is that Momentous’s refund policy says delivered products generally can’t be returned⁵.

Choose Nordic Naturals Ultimate Omega 2X Sport if you want 2,000 mg of EPA plus DHA and a way to send it back. Two softgels give 1,125 mg EPA and 875 mg DHA, and a 60-softgel bottle is $55.95^{6, 11}. That’s about $0.93 per gram and $680.73 a year⁶. NSF lists it with 11 lot numbers⁷. Nordic takes returns of nordic.com orders within 30 days, and its guarantee runs 60 days^{9, 10}. The catch is the price, and Nordic doesn’t say which triglyceride form its oil is or where the gelatin comes from⁶.

Choose Klean Omega if you want a smaller, one-softgel dose. One softgel gives 500 mg EPA and 250 mg DHA, 750 mg together, and a 60-softgel bottle is $44.50^{12, 13}. That’s about $0.99 per gram, but only $270.71 a year at one softgel a day¹². The capsule is fish gelatin from tilapia, and NSF lists two entries with 17 and 6 lots^13–15. The catch is that Klean’s page asks you to log in to add to cart, and returns carry a 15% fee plus shipping^{12, 16}.

None of this shows that one works better than another. What differs is the cost per gram, the dose, the capsule, the certifier listing and what happens if you want to send it back. For what trials found, see what the trials show on creatine, fish oil, vitamin D and magnesium.

Momentous, Nordic Naturals and Klean side by side

Prices are US one-time prices on each maker’s page, before tax and shipping. Momentous, Nordic Naturals and Klean were all checked on November 6, 2026. Subscription prices exist for Momentous and Nordic and aren’t used here. Everything below is a maker’s, certifier’s or regulator’s own statement. None of it is an independent measurement.

These links go to each brand’s own store and earn us no commission.

Which one fits which need

Each suits a different need, and this isn’t a ranking. Start with how much EPA and DHA you want a day, then decide how much a return and a certifier listing matter to you.

• You want about 1.6 g of EPA plus DHA at the lowest cost per gram of the three, in a fish oil NSF lists for all lots: Momentous Omega-3. It’s $39.99 for 60 softgels, about $0.83 per gram^{1, 3, 4}. The catch: it costs about $487 a year, the capsule is bovine gelatin, and delivered products generally can’t be returned^{2, 5}.
• You want about 2 g of EPA plus DHA and a return window: Nordic Naturals Ultimate Omega 2X Sport. It’s $55.95 for 60 softgels, about $0.93 per gram, and NSF lists 11 lot numbers^{6, 7, 9, 10}. The catch: about $681 a year, and Nordic doesn’t say which triglyceride form the oil is⁶.
• You want one softgel a day and the least spent over a year: Klean Omega. It’s $44.50 for 60 softgels of 750 mg EPA plus DHA, about $271 a year^{12, 13}. The catch: about $0.99 per gram, a login to add to cart, and a 15% fee on returns^{12, 16}.
• You’re drug-tested: all three are in NSF’s Certified for Sport database, and you can match the lot number on your bottle to the listed lots where lots are listed^{3, 4, 7, 14, 15}.
• You avoid fish or gelatin: all three contain fish, and Momentous’s and Nordic’s capsules are gelatin. Klean’s capsule is fish gelatin from tilapia, so it isn’t a fish-free option either^{2, 6, 13}.

How cost per gram is worked out

We divided each bottle’s price by the grams of EPA plus DHA it holds, using the label amounts. Momentous holds 48 g (1.6 g a serving, 30 servings), Nordic holds 60 g (2 g a serving, 30 servings) and Klean holds 45 g (0.75 g a serving, 60 servings)^{1, 6, 13}. Total omega-3s would give higher grams, but Klean doesn’t state them, so EPA plus DHA is the one figure all three labels give¹³.

Cost per gram and cost per year point different ways. Klean costs the most per gram, about $0.99, but its label dose is the smallest, so it’s the cheapest over a year at $270.71. Nordic’s dose is the biggest, so it’s the most expensive over a year at $680.73^{6, 12}. To compare them at the same intake, the table scales each to 1 g of EPA plus DHA a day, which is a way to compare and not a dose we recommend.

At that scale a year costs about $304 for Momentous, $340 for Nordic and $361 for Klean. Subscribe & Save prices, tax and shipping aren’t in these numbers^{2, 6, 12}. Momentous’s first Subscribe & Save delivery is $29.99 and later ones are $35.99, per its store listing, which would lower its figures²¹.

How much EPA and DHA, and what the trials used

VITAL randomized 25,871 US adults with no previous heart attack, stroke or cancer, men aged 50 and older and women aged 55 and older, to 1 g a day of marine omega-3 or a placebo for a median 5.3 years¹⁹. The capsule held 460 mg EPA and 380 mg DHA, 840 mg together, per NIH¹⁸. Fish oil didn’t lower major cardiovascular events (hazard ratio 0.92, 95% CI 0.80 to 1.06) or invasive cancer (hazard ratio 1.03, 95% CI 0.93 to 1.13)¹⁹.

Against that 840 mg, Klean’s 750 mg is a little under, Momentous’s 1,600 mg is about 1.9 times as much and Nordic’s 2,000 mg is about 2.4 times as much^{1, 6, 13, 18, 19}. The trial didn’t test any of these products.

A 2021 meta-analysis of seven trials with 81,210 participants linked marine omega-3 supplements to a higher risk of atrial fibrillation (hazard ratio 1.25, 95% CI 1.07 to 1.46)²⁰. The hazard ratio was 1.49 (95% CI 1.04 to 2.15) in trials testing more than 1 g a day and 1.12 (95% CI 1.03 to 1.22) in trials testing 1 g a day or less²⁰. We haven’t confirmed whether those doses count EPA plus DHA or total omega-3s, so this is a rough comparison. By EPA plus DHA on the labels, Momentous’s 1,600 mg and Nordic’s 2,000 mg are above 1 g and Klean’s 750 mg is below it^{1, 6, 13}. The trials enrolled people with heart disease or risk factors for it, not only healthy adults²⁰.

NIH says a typical fish oil capsule holds about 180 mg EPA and 120 mg DHA, and that FDA concluded supplements giving 5 g a day or less of EPA and DHA are safe when used as recommended¹⁸. NIH lists mild side effects, including an unpleasant taste, heartburn, nausea and diarrhea. It also says fish oil might prolong clotting times with warfarin¹⁸. Nordic’s label tells anyone allergic to iodine or taking blood thinners to consult a physician first, and Klean’s tells you to check with a health professional if you’re pregnant, nursing, have a condition or take medication^{11, 13}. Whether and how much to take is a question for your clinician.

Triglyceride form, fish source and the capsule

Fish oil comes in a few chemical forms. NIH says re-esterified triglycerides, natural triglycerides and free fatty acids have somewhat higher bioavailability than ethyl esters, and that all forms significantly raise plasma EPA and DHA¹⁸. So a label that names its form tells you something a bare “fish oil” does not.

Momentous says its oil is in natural triglyceride form and molecularly distilled¹. Klean’s page says triglyceride form but doesn’t say natural or re-esterified^{12, 13}. Nordic’s page names both forms across its fish oils and doesn’t say which applies to this one^{6, 11}. NSF’s listings don’t say.

All three are made from small oily fish. Momentous names anchovy, sardine and mackerel from Norwegian waters, Nordic names anchovies, sardines, mackerel and herring, and Klean names anchovies and sardines and doesn’t say where they’re caught^{1, 6, 13}. Nordic says its fish oils are Friend of the Sea certified, which isn’t independently confirmed here⁶.

The capsule matters if you avoid animal products or have an allergy. Momentous’s softgel is bovine gelatin, Nordic doesn’t state its gelatin source, and Klean’s is fish gelatin from tilapia^{2, 6, 13}. All three contain fish^{2, 11, 13}.

What an NSF listing does and doesn’t tell you

We looked each product up in NSF’s Certified for Sport database instead of relying on a badge on a store page. Momentous has two entries for the 60-count softgel, both with lot “All”. Nordic’s current entry (NUS-01807) has 11 lot numbers and an older entry has 2. Klean has two US entries, with 17 distinct lots in one and 6 in the other^{3, 4, 7, 8, 14, 15}. A bigger number isn’t a better product. It’s how many lots NSF has listed, and you can match the lot number on your bottle to the list.

None of the listings shows a certification date or EPA and DHA amounts^{3, 4, 7, 14, 15}. A sport certification is about what’s in the product and screening for banned substances, not about health effects. NSF doesn’t say how Momentous’s two entries, Nordic’s two or Klean’s two relate, so which one covers your bottle isn’t clear^{3, 4, 8, 14, 15}. Klean’s product page shows no product-specific NSF mark or lot lookup, so NSF’s database is the evidence of its listing¹².

Makers add their own statements. Momentous says every batch is third-party tested and claims IFOS certification, and Nordic says its products are third-party tested and that certificates of analysis are available^{1, 6}. Neither claim is independently confirmed here, and none of the three publishes test results on its product page. For how we weigh these, see how we choose third-party tested supplements. For how to match a lot number to a listing, see are supplements third-party tested.

Returns and guarantees

Nordic is the most flexible. For nordic.com orders you have 30 days from receiving the order to request a return, with a Return Authorization Number, for unmarked, resalable products in their original packaging. Its 60-day satisfaction guarantee covers US purchases from Nordic or an authorized seller^{9, 10}. The pages don’t say who pays return shipping or whether an opened bottle counts as resalable¹⁰.

Klean allows 30 days from receipt with preauthorization and keeps a 15% processing fee plus shipping. Its policy doesn’t say whether an opened bottle qualifies¹⁶.

Momentous is the outlier. Its refund policy says it generally doesn’t accept returns of delivered products, and gives no window⁵. The product page shows a 30-day money-back guarantee with no terms, which the policy doesn’t mention^{1, 5}. If a return matters to you, ask first or choose another.

Does fish oil do anything for healthy adults?

In VITAL, older US adults without heart disease or cancer who took 1 g a day of marine omega-3 had no lower rate of major cardiovascular events or invasive cancer than those on placebo¹⁹. That is why this page compares cost, dose, form and returns and not benefits. A bottle’s label statements about heart, brain or joint health are the maker’s own and haven’t been evaluated by FDA^{1, 6, 12}.

Prescription products at 4 g a day were studied in patients with high cardiovascular risk and high triglycerides^{22, 23}, and those results don’t transfer to over-the-counter fish oil. The trials and their limits are in the supplements evidence review.

What we couldn’t confirm

Momentous’s IFOS certification and per-batch test results aren’t independently confirmed, and NSF doesn’t say which of its two entries matches the current label^{1, 3, 4}. Nordic doesn’t say whether its oil is re-esterified or natural triglyceride, what its gelatin is made from, who pays return shipping or whether an opened bottle qualifies for its guarantee^{6, 10}. Klean doesn’t state total omega-3s, whether its triglyceride form is natural or re-esterified, where the fish are caught, a net weight, or whether its logged-out price applies to every buyer^{12, 13}. None of the three publishes oxidation or heavy-metal results for a given lot. Where a fact wasn’t stated, we left it unknown instead of guessing.

All three prices were checked on November 6, 2026, so check each page before you buy.

Where fish oil fits in the supplements guide

Fish oil is one of four supplements in the third-party-tested supplements guide, alongside creatine, vitamin D and magnesium. Reviews of all three: Momentous Omega-3, Nordic Naturals Ultimate Omega 2X Sport and Klean Omega.

For the same kind of price-per-serving comparison on other supplements, see best creatine supplements and best magnesium glycinate supplements. To see fish oil’s cost next to creatine, vitamin D and magnesium, see what the stack costs a month.

Sources

1. Omega-3 Fish Oil Supplement (60 Capsules) product page Momentous · manufacturer
2. Omega-3 listing on Momentous's store (price and label photo descriptions) Momentous · manufacturer · price read from the store’s product data
3. Momentous Omega-3 - Certified for Sport listing (id 1671910) NSF · certifier
4. Momentous Omega-3 - Certified for Sport listing (id 1597386) NSF · certifier
5. Refund policy Momentous · manufacturer
6. Ultimate Omega 2X Sport | NSF Certified | Nordic Naturals Nordic Naturals · manufacturer
7. Ultimate Omega 2X Sport (NUS-01807) - Certified for Sport listing NSF · certifier
8. Ultimate Omega 2X Sport - Certified for Sport listing (older entry) NSF · certifier
9. Satisfaction Guarantee Nordic Naturals · manufacturer
10. Returns Nordic Naturals · manufacturer
11. Ultimate Omega 2X Sport (60 Softgels), Nordic Naturals Fullscript
12. Klean Omega product page (SKU KA201900-60) Klean Athlete · manufacturer
13. Klean Omega label and Supplement Facts (formula KA201900-60 V2) Klean Athlete · manufacturer
14. Certified for Sport listing: Klean Omega (United States, unflavored) NSF Certified for Sport · certifier
15. Certified for Sport listing: Klean Omega (United States, flavor Other) NSF Certified for Sport · certifier
16. Return Policy Klean Athlete · manufacturer
17. Klean Athlete shop address for omega (forwards to Klean Athlete's Amazon storefront) Klean Athlete · manufacturer
18. Omega-3 Fatty Acids: Fact Sheet for Health Professionals NIH Office of Dietary Supplements · regulator
19. Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer (VITAL) New England Journal of Medicine · randomized trial
20. Effect of Long-Term Marine Omega-3 Fatty Acids Supplementation on the Risk of Atrial Fibrillation in Randomized Controlled Trials of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis Circulation (American Heart Association) · meta-analysis
21. Omega-3 store listing (availability and Subscribe & Save plan prices) Momentous · manufacturer · price read from the store’s product data
22. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia (REDUCE-IT) New England Journal of Medicine, 2019 · randomized trial
23. Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events in Patients at High Cardiovascular Risk: The STRENGTH Randomized Clinical Trial JAMA, 2020 · randomized trial