Does NMN or NR actually extend lifespan?
Short answer: no human trial has shown that. The lifespan claims come from mice. Here's exactly what the human data does show, what the animal data actually found, and where sermorelin fits in: with sources for all of it.
Human trials: what's actually been measured
| Study | N | Design | What it found | Source |
|---|---|---|---|---|
| Fukamizu et al. 2022 | 31 | Safety/dose study, up to 1,250mg/day NMN, 4 weeks | Well-tolerated at studied doses; no serious adverse events. A safety signal, not an efficacy or longevity finding. | Sci Rep 2022 |
| Yoshino et al. 2021 | 25 | RCT, 250mg/day NMN, 10 weeks, prediabetic postmenopausal women | Improved insulin sensitivity and muscle insulin signaling versus placebo. No effect on other metabolic markers tested. Not a lifespan measure. | Science 2021 |
| Huang 2022 | 80 | RCT, dose-ranging NMN, 60 days | Dose-dependent increases in blood NAD+ levels. Confirms NMN raises a biomarker: does not confirm any downstream health or lifespan outcome. | GeroScience 2022 |
| Gu et al. 2024: animal, not human | Mice | Zmpste24⁻/⁻ premature-aging mouse model given NMN | +14% average, +20% median, +10% maximum lifespan versus untreated mice. This is the source of most "NMN extends lifespan" marketing claims: measured in a genetic premature-aging model, not normal aging, and not in humans. | Food & Function 2024 |
No comparable large-scale, long-duration human RCT exists for NR (nicotinamide riboside) lifespan or major health outcomes either: human NR data is similarly limited to short trials on NAD+ levels and tolerability.
What this means in plain language
"Raises NAD+ levels" is real. "Extends lifespan" is not (yet) tested in humans
Multiple human trials confirm NMN and NR supplementation increases blood NAD+: that part of the marketing pitch is accurate. But NAD+ level is a biomarker, not an outcome. No trial has followed a group of healthy humans on NMN or NR for years to measure whether they actually live longer or healthier. That trial doesn't exist yet, for either compound.
The mouse study is real science, but it's not about you
The Gu et al. 2024 lifespan-extension finding is a legitimate, peer-reviewed result. But it was run in mice bred with a rare genetic mutation that causes accelerated aging: a model built to study premature aging mechanisms, not a stand-in for a healthy adult. Extrapolating "+20% median lifespan in premature-aging mice" to "this supplement will help you live longer" is a leap the study itself doesn't support.
Sermorelin is a different evidence category entirely
Sermorelin is a prescription growth-hormone-releasing peptide, not a supplement: its branded version (Geref) was voluntarily withdrawn from the market in 2008, and current use is through compounding, without recent Phase III trial data. In January 2026 the FDA issued guidance requiring documented justification for prescribing compounded sermorelin over an FDA-approved alternative like tesamorelin. That's a meaningfully thinner and more recently-scrutinized evidence base than NMN or NR, which is why this site scores sermorelin clinics separately, with Evidence Match capped low across every provider rather than compared against a branded standard.
Regulatory status: what changed and when
| Date | What happened |
|---|---|
| 2016 | NR (nicotinamide riboside) receives GRAS (Generally Recognized As Safe) status via GRN 000635: uninterrupted since. |
| Nov 1, 2022 | FDA excludes NMN from the dietary supplement definition, based on it having been investigated as a new drug first: effectively barring it from legal sale as a supplement. |
| Sept 29, 2025 | FDA reverses course in a response letter to the Natural Products Association / Alliance for Natural Health USA, restoring NMN's path to legal supplement status. |
| Dec 2–9, 2025 | FDA sends individual confirming letters to ingredient suppliers (e.g. SyncoZymes, Inner Mongolia Kingdomway); published Dec 9, 2025. |
| Jan 2026 | FDA issues guidance on compounded sermorelin requiring documented clinical justification over FDA-approved alternatives (e.g. tesamorelin) before prescribing. |
Practical takeaway: NMN's legal status has been unstable in the last few years: brand due diligence (third-party testing, sourcing) matters more here than in a more settled supplement category. NR has not had this regulatory turbulence.
Decision framework
| Your priority | What the evidence supports |
|---|---|
| Expecting proven lifespan extension | No human trial supports this for NMN or NR. Don't buy on this claim. |
| Raising measurable NAD+ levels | Reasonably well-supported by short human trials for both NMN and NR. |
| Insulin sensitivity in a specific population | One small trial (prediabetic postmenopausal women) showed benefit with NMN, not established as general-population effect. |
| Considering sermorelin | Evidence base is thinner and less current than NMN/NR; FDA now requires documented justification over approved alternatives: ask your prescriber directly about this. |
| Buying an NMN or NR supplement | This is a purchase decision, not a prescribing decision: prioritize third-party testing and purity documentation over marketing claims. |
Sources
- Fukamizu Y, et al. Safety evaluation of β-nicotinamide mononucleotide oral administration in healthy adults. Scientific Reports. 2022.
- Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021.
- Huang H. A multicentre, randomized, double-blind, parallel design trial on NMN. GeroScience. 2022.
- Gu Q, et al. NMN supplementation extends lifespan in a premature aging mouse model. Food & Function. 2024.
- FDA / Federal Register: NMN dietary supplement status correspondence, 2022–2025.
- FDA: Human Drug Compounding guidance, including sermorelin, 2026.
See the products & providers
NMN/NR brand purity comparison, plus CitedRx Scores for sermorelin telehealth clinics.
View the comparison