Four studies worth knowing about, summarised honestly, including the ones that make us look silly. They test ingredients rather than this exact bottle, and wherever that difference matters we have flagged it.
600 mg looked best01
The dose-finding trial, and why we did not pick the biggest number
A multicentre, double-blind, placebo-controlled trial gave 80 healthy adults aged 40 to 65 either 300, 600 or 900 mg of NMN a day for 60 days. Blood NAD rose in every NMN group and rose further with dose. Six-minute walking distance improved, quality-of-life scores improved, and biological age held steady while the placebo group's crept up. No adverse events were attributed to NMN at any dose.
How strong4/5
The catch600 mg came out as the sweet spot, not 900. More was not better, which is the opposite of how supplements are usually sold. We are at 500 mg, one capsule.
Aerobic, not cardiac02
Runners, and where the benefit actually came from
A six-week, four-arm randomised trial put 48 recreationally trained runners on 300, 600 or 1200 mg a day alongside a structured training programme. Ventilatory threshold, a real marker of aerobic endurance, improved with dose against exercise-plus-placebo. The authors traced it to better oxygen use in skeletal muscle rather than any change in heart function.
How strong3/5
The catchEveryone in this trial was training. NMN improved what the training was already doing; it did not replace it.
Yes. The rest, not proven03
Does it actually move NAD in humans?
A 12-week double-blind trial gave 250 mg a day to 36 healthy middle-aged adults. Serum nicotinamide, a downstream marker of NAD metabolism, rose significantly, which is the direct confirmation that oral NMN feeds the pathway in people. Arterial stiffness trended better, more so in those with higher BMI or blood glucose.
How strong3/5
The catchThe arterial stiffness result did not reach statistical significance across the whole group. A trend is a reason to keep looking, not a claim.
Afternoon won04
Timing mattered more than we expected
A 12-week trial in 108 Japanese adults aged 65 and over compared morning against afternoon dosing at 250 mg a day, against placebo. Afternoon intake produced the meaningful results: less drowsiness and better lower-limb function on sit-to-stand, at moderate-to-large effect sizes. Sleep quality trended better too. Compliance was above 95%.
How strong3/5
The catchThis was an over-65 group, so it may not transfer to a 35-year-old. But if you are going to pick a time, the evidence points at the afternoon rather than with breakfast.
