Head to head
NMN against Nicotinamide
A precursor sold for ageing against a cheap B3 form with an actual phase 3 result, in skin cancer prevention rather than ageing. Nicotinamide cut new non-melanoma skin cancers by 23 percent over 12 months, and the benefit stopped when the tablets stopped.
Column A
NMNNicotinamide Mononucleotide
A direct NAD+ precursor studied for metabolic and physical-function benefits in aging, with early human trials and a contested regulatory status in the US.
Column B
NicotinamideNicotinamide, the amide form of vitamin B3
In the ONTRAC phase 3 trial, 500 mg twice daily cut the rate of new non-melanoma skin cancers by 23 percent over 12 months in 386 high-risk patients, with no benefit once the tablets stopped. The identical trial in 158 organ transplant recipients found nothing, and no trial has ever tested nicotinamide against an ageing outcome.
Side by side, on the facts we can check
| Attribute | NMN | Nicotinamide |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Not an approved drug; US supplement status contested | Not an approved drug for skin cancer prevention in the United States. It is a recognised form of the vitamin niacin, sold over the counter, and included in multivitamins and topical cosmetics. The ONTRAC dose is an over-the-counter dose used off-label. |
| Half-life | Short | About 4 hours in plasma, which is why the skin cancer trials dosed it twice a day rather than once. |
| Molecular weight | 334.2 Da | 122.1 Da |
| Mechanism | Converts to NAD+ through the salvage pathway, aiming to restore NAD+ levels that decline with age. | Nicotinamide enters NAD synthesis through the salvage pathway. NAMPT, nicotinamide phosphoribosyltransferase, converts it to NMN, and NMNAT enzymes convert NMN to NAD. NAMPT is the rate-limiting step, which is the structural reason more nicotinamide does not translate linearly into more NAD: the bottleneck is enzymatic, not substrate supply. Separately, nicotinamide is the product released when sirtuins, PARPs and CD38 consume NAD, and it inhibits sirtuin deacetylation by binding a conserved pocket adjacent to NAD and switching the enzyme toward base-exchange chemistry rather than deacetylation. In skin, the proposed cancer-prevention mechanism is different again and does not depend on systemic NAD at all: nicotinamide supports PARP-dependent repair of UV-induced DNA damage and reduces UV-induced cutaneous immunosuppression. |
| Human studies cited | 2 | 4 |
| Legal status, US | Not approved; FDA excluded it from the supplement definition (2022) | Sold as a supplement |
Frequently asked questions
What is the difference between NMN and Nicotinamide?
NMN: A direct NAD+ precursor studied for metabolic and physical-function benefits in aging, with early human trials and a contested regulatory status in the US. Nicotinamide: In the ONTRAC phase 3 trial, 500 mg twice daily cut the rate of new non-melanoma skin cancers by 23 percent over 12 months in 386 high-risk patients, with no benefit once the tablets stopped. The identical trial in 158 organ transplant recipients found nothing, and no trial has ever tested nicotinamide against an ageing outcome.
Which has stronger research evidence, NMN or Nicotinamide?
This database does not grade compounds. It counts what was run in people: 2 of the 3 studies cited on the NMN profile were human work, against 4 of 5 for Nicotinamide. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are NMN and Nicotinamide FDA-approved?
NMN: Not an approved drug; US supplement status contested. Nicotinamide: Not an approved drug for skin cancer prevention in the United States. It is a recognised form of the vitamin niacin, sold over the counter, and included in multivitamins and topical cosmetics. The ONTRAC dose is an over-the-counter dose used off-label..
Related posts
Blog articles that cover NMN or Nicotinamide, newest first.
- Longevity / Sep 8, 2026 / 9 minThe Rapamycin Dosing Debate: What PEARL Tested, the Bioavailability Problem, and What Is Unproven
- Metabolic / Sep 8, 2026 / 7 minSLU-PP-332 and 5-Amino-1MQ: Two 'Peptides' That Are Not Peptides, and What the Mouse Data Actually Show
- Longevity / Sep 8, 2026 / 8 minNMN vs NR vs NAD+: The 2026 Head-to-Head Human Trials, and Who Funded the Comparisons
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.