Where can you get NMN?
He owns part of the company that makes patented NMN which is just another form of NR which is a another form of very cheap Niacin.
He also owns part of the company that claims he is rolling back his biological clock.
That's not science, that's marketing and profiteering.
NAD production slows down with age and illness. All he is doing is supplementing what was produced more easily by a younger body.
There are a many other factors to aging, most of which cannot be changed (yet) by science.
Nowadays the small pains and aches go away in a few hours, like when I was some 15 years younger. But if I stop the supplementation, the situation reverts to the old bad standard within a month or so.
I also noticed some effect on my visual acuity.
I know this is N == 1, hard to measure precisely and subject to a possible placebo effect.
The key to NAD supplementation is the people who need it are older or ill.
There are a lot of other processes in such bodies that become deficient too.
None of the supplement methods for NAD, Niacin, NR, NMN will boost levels beyond what your body will use.
This is what the NAD cycle looks like, you can see NA (niacin) vs NR vs NMN are each closer to production but the end result is the same of what ends up in the blood vs organs like liver.
https://www.lifespan.io/wp-content/uploads/2019/06/NAD_schem...
There are wild arguments, even with scientific rigor, about NR vs NMN ability to get into cells. It is more likely that genetics matters and it varies from person to person and what else is in their diet.
My impression of Sinclair is that he likes public attention too much and often reports on work in progress with too much certainty, but results like this [1] seem to be fairly impressive.