Yes, lots has been done in vitro, little in vivo. Given the failure of NR in the ITP studies its going to take a lot for me to be convinced that NMN or NR are worth the money.
I doubt anyone below the age of 60 is short of NAD+
I tried it once - made me have to get up in the night for the toilet - suspect I was just urinating it all away as I didn’t need it. As soon as I stopped it, didn’t need to get up in the night anymore.
I have seen on other forums in the past that it does appear to be beneficial to people in their 80’s.
I have a strong suspicion that NMN is the culprit for my swollen prostate that flared up after I started using it. It is that or CA-AKG that I also started with at the same time a year ago or so.