I'm very intrigued by the idea of NR and NMN. Allow me to explain my current state of knowledge: I'm a biochemistry student so I know the roles that NAD is most famous for: glycolysis, gluconeogenesis, citric acid cycle, fatty acid oxidation, fatty acid synthesis, and the electron transport chain. I know that the amount of NAD in the body decreases over time and it's intuitive that this would cause a lot of problems and that reversing it would partially reverse aging.
So far I've just read around 15-20 abstracts, a couple news articles, and this: http://alivebynature.com/about-niagen/
What I want to know is:
1. Are there any practical differences between NR and NMN? My understanding is that NMN is just phosphorylated NR and the body turns NMN into NR. Doesn't that make them functionally identical?
2. I found two human studies on NR. Have any human studies on NMN been released so far?
3. My understanding is that there are currently multiple NMN studies going on and no NR studies. Why? What gives?
4. What's the right age to start taking NR / NMN? It's pointless to take it when you're young right?
5. What's the right dose? One study examined in the article linked above found that there weren't extra benefits beyond 300mg.
6. When will more human studies be published?
7. What's the connection between NAD and sirtuins?
8. Any chance this is overhyped?
If anyone can answer or link me an answer to any of these questions, I'd like that. Even just one question answered will help. If there's a book or a website that actually answers these questions in clearly-explained manner, that would be preferable.