Head to head
Niacin against Nicotinamide Riboside
The oldest and the newest NAD precursors. Niacin is the only compound in this pathway ever tested against cardiovascular events, in 29,000 people across two trials, and it prevented none; nicotinamide riboside has never been tested against an event of any kind.
Column A
NiacinNicotinic acid, niacin, the acid form of vitamin B3
The only compound in the NAD pathway ever tested against hard cardiovascular outcomes, in 25,673 patients in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every lipid it was supposed to move and prevented no events in either trial, and HPS2-THRIVE found excess serious adverse events including infection and bleeding.
Column B
Nicotinamide RibosideNicotinamide Riboside (NR)
A well-studied NAD+ precursor that reliably raises NAD+ in humans. Raising the molecule is proven; the mouse lifespan programme that tested it found no effect.
Side by side, on the facts we can check
| Attribute | Niacin | Nicotinamide Riboside |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Extended-release nicotinic acid is an FDA-approved prescription lipid drug in the United States, though its clinical use collapsed after AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The extended-release niacin with laropiprant combination used in HPS2-THRIVE was withdrawn worldwide after the trial reported. | Sold as a supplement; not an approved drug |
| Half-life | 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. | Short |
| Molecular weight | 123.1 Da | 255.2 Da |
| Mechanism | Nicotinic acid enters NAD synthesis through the Preiss-Handler pathway rather than the NAMPT salvage route, which is why it is a genuinely potent NAD booster and why a 2026 human study proposed that gut bacterial conversion of NR and NMN into nicotinic acid may be how those two expensive precursors work at all. Its lipid effects are separate and act mainly through inhibition of adipocyte lipolysis and hepatic diacylglycerol acyltransferase, reducing free fatty acid flux to the liver and VLDL output. The flush is a third, distinct mechanism: nicotinic acid activates the receptor GPR109A on immune cells in skin, releasing prostaglandins D2 and E2 that dilate cutaneous vessels. Mouse knockout work established each link in that chain. The laropiprant in HPS2-THRIVE was a prostaglandin D2 receptor antagonist added to block exactly this, which worked for the flush and did nothing for the outcomes. | Converts to NAD+ through the salvage pathway, restoring NAD+ that declines with age and supporting mitochondrial and repair enzymes. |
| Human studies cited | 5 | 4 |
| Legal status, US | FDA-approved prescription lipid drug, also sold over the counter as a supplement | Sold as a dietary supplement |
Frequently asked questions
What is the difference between Niacin and Nicotinamide Riboside?
Niacin: The only compound in the NAD pathway ever tested against hard cardiovascular outcomes, in 25,673 patients in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every lipid it was supposed to move and prevented no events in either trial, and HPS2-THRIVE found excess serious adverse events including infection and bleeding. Nicotinamide Riboside: A well-studied NAD+ precursor that reliably raises NAD+ in humans. Raising the molecule is proven; the mouse lifespan programme that tested it found no effect.
Which has stronger research evidence, Niacin or Nicotinamide Riboside?
This database does not grade compounds. It counts what was run in people: 5 of the 6 studies cited on the Niacin profile were human work, against 4 of 5 for Nicotinamide Riboside. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Niacin and Nicotinamide Riboside FDA-approved?
Niacin: Extended-release nicotinic acid is an FDA-approved prescription lipid drug in the United States, though its clinical use collapsed after AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The extended-release niacin with laropiprant combination used in HPS2-THRIVE was withdrawn worldwide after the trial reported.. Nicotinamide Riboside: Sold as a supplement; not an approved drug.
Related posts
Blog articles that cover Niacin or Nicotinamide Riboside, newest first.
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.