Quick answer
No time of day has been shown to change how much NMN raises blood NAD+. The one trial that compared timing gave 108 older adults 250 mg either before noon or in the evening. Some measures changed most in the evening group, but the trial was small, funded by the maker and did not measure NAD+.1
Key facts
- Trials have given NMN once a day before breakfast, or as 125 mg in the morning and 125 mg in the evening.2,3
- Breakdown products of nicotinamide rose in the blood within 5 hours of a single dose.4
- Europe's bioavailability study gave single doses in water after an overnight fast.5
- With 125 mg taken twice a day, blood NAD+ stayed higher through 12 weeks.3
The one trial that compared morning and evening
In a 12-week trial of 108 adults in their 70s, 250 mg was taken either before noon or between 6 pm and bedtime. Chair-stand times and drowsiness scores changed most in the evening NMN group, but the evening placebo group's drowsiness scores also changed, and the NMN maker funded the trial.1
The paper's summary calls that later window the afternoon. Chair-stand times got faster in all four groups, placebo included, and blood NAD+ was not measured, so the trial cannot say whether timing changed how much NMN reached the blood.1
Read the evening result as a lead for further study, not a rule. It has not been repeated.
How the trials gave it
Trials have given NMN once a day before breakfast with water, or split into a morning and an evening dose.2,3
| Trial | Amount | When |
|---|---|---|
| 80 adults, 60 days | 300 to 900 mg | Once a day before breakfast, with water |
| 30 adults, 12 weeks | 250 mg | 125 mg in the morning and 125 mg in the evening |
| 36 adults, 12 weeks | 250 mg | 125 mg twice a day |
| 11 adults, 12 weeks | 250 mg | Once a day in the morning |
| 108 adults in their 70s, 12 weeks | 250 mg | Once a day, before noon or from 6 pm to bedtime |
Both patterns raised blood NAD+: one dose a day in the 60-day trial and the 11-person study, and two half doses in the 30-person trial.2,3,7
With or without food
Europe's bioavailability study gave single doses in water after an overnight fast, and the 60-day trial dosed before breakfast. We found no trial that compared taking NMN with a meal against an empty stomach, so there is no evidence either way.2,5
Europe's assessors also noted that how NMN holds up in the strong acid of an empty stomach was not tested.5
The hours after a dose
After single doses of 100, 250 and 500 mg, two breakdown products of nicotinamide rose in the blood within the 5 hours measured, more at the higher doses.4
That shows the body handles NMN within hours. How long NAD+ itself stays raised after one dose was not reported in the trials we read, which is another reason no ideal hour can be named.4
Picking a time
In trials, blood NAD+ was measured after weeks of daily use, not after a single dose. A time you can keep to every day is the practical choice, whether that is with breakfast, before it, or in the evening.2,3
What’s in ours
- NMN: β-Nicotinamide Mononucleotide, 500 mg per serving, from the label
Our label says to take one capsule a day with water and does not name a time.
Before you choose a time
- If you take medicine for diabetes, ask your doctor first: in a small trial of morning doses, insulin measured after lunch rose7
- If you are pregnant, breastfeeding or under 18, ask your doctor before taking NMN at any time of day
Questions people ask
Should I take NMN in the morning or at night?
Both were used in trials that raised blood NAD+. The only head-to-head trial found larger changes in chair-stand times and drowsiness with evening doses, but it was small, funded by the maker and not repeated.1,2
See what we make
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Sources
- Kim M, Seol J, Sato T, Fukamizu Y, Sakurai T, Okura T. Effect of 12-Week Intake of Nicotinamide Mononucleotide on Sleep Quality, Fatigue, and Physical Performance in Older Japanese Adults: A Randomized, Double-Blind Placebo-Controlled Study. Nutrients. 2022;14(4):755. Opened 2026-10-07.
- Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. Geroscience. 2023;45(1):29-43. Opened 2026-10-01.
- Okabe K, Yaku K, Uchida Y, et al. Oral Administration of Nicotinamide Mononucleotide Is Safe and Efficiently Increases Blood Nicotinamide Adenine Dinucleotide Levels in Healthy Subjects. Front Nutr. 2022;9:868640. Opened 2026-10-07.
- Irie J, Inagaki E, Fujita M, et al. Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocr J. 2020;67(2):153-160. Opened 2026-10-07.
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck D, Bohn T, Cámara M, et al. Safety of beta-nicotinamide mononucleotide (β-NMN) pursuant the regulation (EU) 2015/2283 and the bioavailability of nicotinamide from this source in the context of Directive 2002/46/EC. EFSA J. 2026;24(5):e10007. Opened 2026-10-01.
- Katayoshi T, Uehata S, Nakashima N, Nakajo T, Kitajima N, Kageyama M, Tsuji-Naito K. Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial. Sci Rep. 2023;13(1):2786. Opened 2026-10-01.
- Yamane T, Imai M, Bamba T, Uchiyama S. Nicotinamide mononucleotide (NMN) intake increases plasma NMN and insulin levels in healthy subjects. Clin Nutr ESPEN. 2023;56:83-86. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.