NMN supplements

What is NMN, and what does it do?

NMN is a form of vitamin B3. Your body turns it into NAD+, a molecule that sits inside every cell and helps turn food into energy. NAD+ also helps cells repair themselves.

That is how it works, not what it does for you. Those are two different things, and the gap between them is the whole story of this category.

NMN is also not the only way to get NAD+. Plain vitamin B3, which you get from food and from most B-complex tablets, feeds the same system. So does nicotinamide riboside, or NR. The TGA lists all of them as building blocks for NAD+.

What do the studies actually show?

Two things, and they pull in opposite directions.

The first is solid. NMN does raise the NAD+ in your blood, and several trials have measured it.

The second is the part the marketing skips. When researchers went looking for a change people could feel or measure, they mostly did not find one. In 2025 a team pooled ten trials in adults whose average age was over 60 and concluded the evidence does not support NMN for muscle size or strength. Grip strength, walking speed, muscle mass and how quickly people could stand up from a chair all came back with no benefit.

Two single trials tell the same story. One 12-week trial of 60 older adults was built around a stepping test, and found no difference from a dummy pill. Walking time and sleep scores did improve, but those were secondary measures rather than the one the trial was designed to answer, which is weaker evidence. A second 12-week trial, in 36 middle-aged adults, reported on artery stiffness. Across the whole group the result did not reach significance; the improvement sat in a smaller group of people with higher BMI or blood glucose, and its authors concluded NMN may ease artery stiffness on that basis.

One trial does point the other way, and we would rather show it than pretend the evidence is one-sided. Over 60 days, 80 healthy middle-aged adults took 300, 600 or 900 mg a day. Every dose raised blood NAD+ above a dummy pill, and every dose improved how far people could walk in six minutes. A general-health questionnaire and a biological-age calculator moved in NMN's favour as well. Insulin resistance did not change.

Each of those findings is listed with a link to its original study, so you can read them yourself.

How much, and for how long?

The two 12-week trials on this page used 250 mg a day. In the 2025 review, every NMN trial used 250 mg a day except one, which used 2000 mg a day for four weeks and also found no change in strength or muscle. The 60-day trial that found a walking benefit used 300 mg and above.

Australia now puts a ceiling on it. Any listed medicine containing NMN must be taken by mouth, must not exceed 500 mg a day, must recommend 12 weeks or less, and must be for adults only. So the doses that performed best in that 60-day trial sit above what an Australian listed medicine is allowed to recommend.

The products here give 250 mg or 500 mg a serve, and one does not state a dose at all. Nobody has run 250 mg against 500 mg head to head, so if you are choosing between them, you are choosing without a direct comparison. Two of the sports-food products direct up to two serves a day, which would put you above the listed-medicine ceiling; read your own label rather than assuming.

Does purity matter, and how would you know?

Brands print numbers like 99.9 per cent pure on NMN packs. Until recently that was just a brand describing itself.

The TGA now publishes a compositional guideline for NMN, which sets a real standard: between 98 and 102 per cent NMN, no more than 1 per cent total impurities, and limits on arsenic, lead, mercury and cadmium.

So if purity is your reason for picking one brand over another, ask that brand for its certificate of analysis. A brand that tests its batches will have one.

Capsule, tablet or powder?

Capsules are already measured out and the easiest to keep taking every day, which matters when the evidence rests on 12 weeks of daily use.

Powder lets you take part of a serve, which is handy if you want 250 mg out of a 500 mg product.

Slow-release tablets spread the dose across the day instead of delivering it all at once.

No study we have read compared these formats against each other. Pick the one you will actually keep taking.

How do I tell a listed medicine from a sports food?

Turn the pack over and look for an AUST L number.

If it has one, it is a listed medicine. It is entered on the Australian Register of Therapeutic Goods, and it is allowed to use wording the TGA has approved. There is a further catch worth knowing: until 10 December 2027, NMN may only be used in a listed medicine where SyncoZymes (Shanghai) is the sponsor, or has authorised the sponsor and notified the TGA.

If there is no AUST L number, the product is not a listed medicine. Some are sold as formulated supplementary sports foods, which sit under the food rules and may carry no therapeutic wording at all. The TGA also warns that goods referring to NMN that are not on the register may be unapproved or unlawfully supplied, so the register is the check that matters rather than the category name.

Either way, the pack and the register tell you what the marketing cannot.