Short answer: In the only head-to-head study, 14 days of NMN or NR raised blood NAD+ by a similar amount in 65 healthy adults; most authors work for Nestlé.1 Both are well tolerated in short trials.23 Health benefits are unproven: NMN trials show few metabolic changes, and a 52-week NR trial in Parkinson disease did worse than placebo.4
| NMN (nicotinamide mononucleotide) | NR (nicotinamide riboside) | |
|---|---|---|
| Raises blood NAD+? | Yes, by a similar amount to NR over 14 days1 | Yes, by a similar amount to NMN over 14 days; also in a 6-week crossover trial13 |
| Best-known trial | 10 weeks in postmenopausal women with prediabetes: muscle insulin sensitivity improved5 | 52 weeks in 410 people with early Parkinson disease, 500 mg twice a day: scores worsened slightly more than with placebo4 |
| Pooled results | 15 trials, 250 to 2,000 mg a day for up to 24 weeks: no change in weight, glucose, HbA1c or lipids; small drop in diastolic blood pressure2 | No pooled analysis in the sources checked |
| Side effects in trials | No increase in adverse events or liver enzymes in short trials2 | Well tolerated over 6 weeks; fewer serious adverse events than placebo over 52 weeks34 |
| Industry ties shown in abstracts | Two authors of the 2021 trial report patent interests, one an NMN patent application5 | Two NOPARK authors hold NR patents licensed to Niagen Bioscience4 |
In a randomized, open-label study in 65 healthy adults, 14 days of NR or NMN raised blood NAD+ by a similar amount, while plain nicotinamide did not. The authors suggest both work partly through gut bacteria, which turn them into nicotinic acid. Most authors are Nestlé employees.1
NMN. In a 10-week trial in postmenopausal women with prediabetes and overweight or obesity, NMN raised muscle insulin sensitivity, while placebo did not.5 A 2026 meta-analysis of 15 trials found NMN well tolerated but with no clear effect on weight, glucose, HbA1c or cholesterol; diastolic blood pressure fell slightly.2
NR. A 6-week crossover trial in healthy middle-aged and older adults found NR well tolerated and raised NAD+ metabolism, with hints on blood pressure and artery stiffness for future trials.3 The largest trial, NOPARK, gave 500 mg twice a day or placebo for 52 weeks to people with early Parkinson disease. Disease scores rose 2.72 points more with NR than with placebo, and non-motor symptoms worsened more.4
On NAD+ levels they look similar in the one direct comparison. Neither has shown a clear health benefit in a large trial, and the biggest NR trial was negative. This is general information, not personal advice. More detail: the NMN (Nicotinamide Mononucleotide) and Nicotinamide Riboside (NR) guides.