Are NAD+ supplements (NMN/NR) worth it?

NMN and NR supplements do deliver on their promise at the level of your blood: in multiple randomised studies in middle-aged and older adults, NAD+ levels rose noticeably. That is fairly well established. The problem lies one step further along: higher NAD+ levels in the blood do not automatically reflect what is happening in your muscles, brain or other tissues, and there is so far no convincing evidence that those higher levels also lead to anything you can feel or measure, such as better muscle strength, sharper cognition or improved blood lipids. Most clinically focused studies in older adults found no effect on those outcomes.

There is one exception worth noting: a study in women with prediabetes found improved insulin sensitivity after NMN use. That is a relevant result, but it has not yet been replicated by other research groups, so it is too early to draw conclusions from it.

On safety: short-term studies report that NMN and NR are well tolerated. Nothing is known about use over multiple years, and in laboratory research there is a theoretical question of whether higher NAD+ levels could stimulate existing cancer cells. This has not been demonstrated in humans, but it has not been fully ruled out either. If you want to try it: it is available without a prescription at pharmacies or online. Look for a clearly stated dose per serving and preferably a brand with independent quality control, because as an unregistered supplement, purity varies considerably between manufacturers.

The honest summary is that with this supplement you are paying for an expected mechanism, not for proven outcomes in humans. That could change as longer trials are published, because the field is still moving. If you would like to know when there is news on this front, I can keep you informed.