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.
The stuff I got was from Alive By Science, now Renue, and they claim theirs is shelf stable. https://renuebyscience.com/how-long-does-our-nmn-retain-its-...