Sure - you can find many NR and NMN supplements on AMZN for example.
NMN has gained popularity over NR, I believe mostly due to longer shelf life.
Elysium and TruNiagen are two famous brands, that IIR were sueing each other at some point? I take another/cheaper NMN supplement.
Caveat emptor - there's really no way to tell what you're getting from many of these - and even if you're getting pure ingredients, the jury is still out.
For the past couple of years I’ve been taking Nicotinamide Riboside I buy on Amazon and it has basically eliminated inflammation and pain I used to get in my hands, wrists, and sometimes elbows. FWIW, I’m going to be 52 this year.
You can get NMN at most supplement places. NootropicsDepot sells it for example.