Does NMN Increase Testosterone? Human Trial Data + My Blood-Test Experience

Short answer: as of September 2026, I have not found convincing human evidence that oral nicotinamide mononucleotide (NMN) increases testosterone. One randomized placebo-controlled human trial measured testosterone directly and found no significant treatment effect. My own repeated blood tests while taking NMN also did not show a clear increase, although a personal experiment cannot establish causality.

My own NMN and testosterone experiment

I originally became interested in this question after seeing claims that 500 mg or more of NMN could raise testosterone substantially, particularly when baseline testosterone was low. I took NMN for about two months and repeatedly measured venous total and free testosterone. My baseline was relatively low, so an increase would have been easy to welcome. I did not observe a statistically convincing rise or fall.

This is an N=1 observation, not a clinical trial. Testosterone varies with time of day, sleep, calorie intake, illness, training, body weight and laboratory variation. Still, it is useful to publish a negative personal result rather than only success stories.

The most direct human trial I found

A randomized, double-blind, placebo-controlled trial enrolled 36 healthy men and women aged 40–59. Participants received 250 mg/day NMN or placebo for 12 weeks. Testosterone and several other hormones were measured.

In the participants who completed the trial, mean testosterone changed from 212.2 to 208.2 ng/dL in the NMN group and from 143.1 to 139.7 ng/dL in the placebo group. The between-group result was not significant (p = 0.933). The authors reported no significant hormonal changes after the intervention. Randomized trial of 12-week NMN supplementation.

Because this study included both men and women and was not designed specifically as a male-hypogonadism trial, it does not prove that NMN can never affect testosterone in a subgroup. But it is direct human evidence against the claim that NMN routinely or dramatically boosts testosterone.

An acronym trap in the older version of this article

I need to correct one mistake from the original version of this page. I had cited a PCOS study containing the abbreviation “NMN,” but in that paper NMN meant normetanephrine, a catecholamine metabolite. It did not mean nicotinamide mononucleotide. That study therefore tells us nothing about NMN supplements and testosterone. It has been removed from the evidence base here.

What do other human NMN trials show?

Human trials do support a different claim: oral NMN can increase blood NAD-related metabolites in some settings. For example, a 12-week placebo-controlled trial of 250 mg/day in healthy adults found significantly higher whole-blood NAD+ after NMN supplementation and no obvious safety abnormalities. Testosterone was not the therapeutic outcome. NMN and blood NAD+ in healthy subjects.

Other randomized studies have investigated sleep, fatigue, walking speed, insulin sensitivity and physical function. Those results may be interesting for NMN as a NAD+ precursor, but they should not be repackaged as evidence that NMN raises testosterone when testosterone was not the endpoint.

Why do testosterone claims about NMN exist?

There are plausible biological stories and animal experiments involving NAD+ metabolism, reproductive aging and testicular injury. There are also individual reports of higher testosterone after starting NMN. But an after-versus-before change in one person can be caused by many things, and animal rescue experiments do not establish a testosterone-boosting effect in healthy men.

If you want to test NMN on yourself

A cleaner self-experiment would use repeated baseline and follow-up blood draws at the same time of day and preferably the same laboratory, while keeping sleep, training and calorie intake as stable as possible. Total testosterone alone is also incomplete; SHBG and calculated or measured free testosterone can help interpret a change. Even then, an N=1 result is evidence about you, not proof of a general effect.

Bottom line

NMN is not currently an evidence-based testosterone booster. The most direct randomized human data I found measured testosterone and showed no significant effect after 12 weeks of 250 mg/day. My own blood-test experience points in the same direction. That conclusion can change if a future well-designed trial in men with low testosterone shows otherwise, but the current evidence does not justify claims of a 20%, 50% or “doubling” effect.

Core sources

• Randomized 12-week NMN trial with testosterone measurements
• NMN supplementation and blood NAD+ levels
• EFSA review of human NMN safety studies