Omega-3 vs Niacin
Written by Aaron CuhaReviewed Sep 2026
The short answer
Two supplements that change blood fats, with the same lesson in their history. Both reliably move the blood numbers they target. Both failed to prevent heart attacks and strokes in large trials. Niacin's failures were HPS2-THRIVE and AIM-HIGH. Omega-3's two large trials reached opposite answers, and the difference may come down to the dummy oil used.
- Omega-3 people
- 34,050
- Omega-3 nulls
- 1
- Niacin people
- 29,087
- Niacin nulls
- 0
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
3 completed trials, 34,050 people given it
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
Slow-release nicotinic acid is an FDA-approved prescription cholesterol drug in the United States. But doctors mostly stopped using it after two large studies, AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The mix of slow-release niacin and laropiprant tested in HPS2-THRIVE was pulled from sale worldwide after that study reported.
First-hand reports are counted on each profile and never added together. This page sets two published records side by side. It does not pick a winner.
Column A
Omega-3Long-chain omega-3 fatty acids (EPA and DHA)
Two big heart studies of fish oil drugs came to opposite answers, and the dummy pill may be why. People with more omega-3 in their blood tend to live longer, but the supplements mostly have not helped. The risk of an irregular heartbeat is real and grows with the dose.
Column B
NiacinNicotinic acid, niacin, the acid form of vitamin B3
The only NAD-pathway product ever tested against real heart outcomes, in 25,673 people in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every blood fat it was meant to move. It prevented no heart attacks or strokes in either study. In HPS2-THRIVE it caused extra serious side effects, including infections and bleeding.
Side by side, on the facts we can check
| What we compare | Omega-3 | Niacin |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Icosapent ethyl and omega-3-acid ethyl esters are FDA-approved prescription drugs for very high triglycerides, a type of blood fat. Icosapent ethyl is also approved to lower the risk of heart and blood vessel problems. Over-the-counter fish oil is a dietary supplement and is not approved to treat anything. | Slow-release nicotinic acid is an FDA-approved prescription cholesterol drug in the United States. But doctors mostly stopped using it after two large studies, AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The mix of slow-release niacin and laropiprant tested in HPS2-THRIVE was pulled from sale worldwide after that study reported. |
| Half-life | Roughly 2 to 3 days for plasma phospholipid EPA and DHA. Red cell membrane incorporation, which is what an omega-3 index measures, is far slower and takes about 120 days to reach steady state and about the same to wash out, so retest the index at four months rather than at one. | Under an hour for immediate-release nicotinic acid. Extended-release formulations were built specifically to stretch that out and blunt the flush, and the dose is not interchangeable between forms. |
| Molecular weight | 302.5 Da for EPA and 328.5 Da for DHA as free acids. Supplement forms are ethyl esters or triglycerides, which differ in absorption. | 123.1 Da |
| How it works | EPA and DHA are the two main omega-3 fats in fish oil. They build into the outer wall of your cells. There they push out another fat, arachidonic acid, that feeds swelling signals. They are also made into molecules that help switch swelling off once its job is done. EPA makes the liver produce less triglyceride, a blood fat. That is why high-dose prescription versions are used for very high triglycerides. DHA is a main building block of the eye and brain. The same changes to cell walls also change how heart cells fire. That is the most likely reason for the irregular heartbeat finding. | Niacin gets turned into NAD by its own route, called the Preiss-Handler pathway, not the NAMPT recycling route. That is why it is a strong NAD booster. A 2026 study in people suggested gut bacteria may turn NR and NMN into niacin, and that this may be how those two pricey products work at all. Niacin's effect on blood fats is separate. It mainly slows the release of fat from fat cells and slows fat-making in the liver. So less fat flows to the liver, and the liver sends out fewer fat-carrying particles. The flush is a third, separate action. Niacin switches on a receptor called GPR109A on immune cells in the skin. They release chemicals called prostaglandins that open up the skin's blood vessels. Work in mice with genes switched off proved each link in that chain. The laropiprant in HPS2-THRIVE blocked one of those prostaglandins to stop the flush. It stopped the flush and did nothing for the outcomes. |
| Studies in people | 5 | 5 |
| Evidence | Strong: 3 completed trials, 34,050 people given it | Strong: 2 completed trials, 29,087 people given it |
| Legal status, US | Sold as a supplement | FDA-approved prescription cholesterol drug, also sold over the counter as a supplement |
Frequently asked questions
What is the difference between Omega-3 and Niacin?
Omega-3: Two big heart studies of fish oil drugs came to opposite answers, and the dummy pill may be why. People with more omega-3 in their blood tend to live longer, but the supplements mostly have not helped. The risk of an irregular heartbeat is real and grows with the dose. Niacin: The only NAD-pathway product ever tested against real heart outcomes, in 25,673 people in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every blood fat it was meant to move. It prevented no heart attacks or strokes in either study. In HPS2-THRIVE it caused extra serious side effects, including infections and bleeding.
Which has stronger research evidence, Omega-3 or Niacin?
Each compound gets a band worked out from facts we counted, with the math shown. Omega-3 is Strong (3 completed trials, 34,050 people given it). Niacin is Strong (2 completed trials, 29,087 people given it). That counts how much has been done in people. It does not rate whether either one works, and neither one is called the winner.
Are Omega-3 and Niacin FDA-approved?
Omega-3: Icosapent ethyl and omega-3-acid ethyl esters are FDA-approved prescription drugs for very high triglycerides, a type of blood fat. Icosapent ethyl is also approved to lower the risk of heart and blood vessel problems. Over-the-counter fish oil is a dietary supplement and is not approved to treat anything.. Niacin: Slow-release nicotinic acid is an FDA-approved prescription cholesterol drug in the United States. But doctors mostly stopped using it after two large studies, AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The mix of slow-release niacin and laropiprant tested in HPS2-THRIVE was pulled from sale worldwide after that study reported..
Reviewed Sep 2026. This page puts two published records side by side. It is for learning, and it is not medical advice. When this site shows a dose, it is the dose a trial or a clinic actually used, or what people say they did, with the source attached. None of it tells you what to take.