Approximately 1 gram of NR in humans has been shown to increase NMN and NAD+ levels.

“We know that if you take it as a supplement to swallow the pill, either 250 milligrams per day or a gram, there's no apparent negative side effects, and in fact, you will raise NAD levels in blood tests.”

“With NR there've been a handful of studies in humans showing that low dose, 250 milligrams per day, up to a pretty large dose, a gram a day, does raise NAD levels, but it takes about 9 to 10 days to get to those peak levels. What we've also seen is, or others have seen, is lower inflammation as well as some other markers such as minor changes in body composition.”

“So NR is different from NMN. Let's go through that again. When you want to make NAD, what the cell does is it takes vitamin B3, or niacin, or nicotinamide, turns it into NR. So the nicotinamide gets now a sugar, ribose. And then to make NMN, it puts a phosphate, which is phosphorus and oxygen. And then it combines that together to form NAD. So those are the various steps. Now, what NR is, it's a couple of steps back from NAD. And so when you take NR, it's made into NMN, made into NAD. But it's been shown in humans by taking large doses, about a gram of NR, you'll make NMN, and you'll make higher levels of NAD, which is shown to be important in this study in ALS patients.”

“it was a good study placebo-controlled they had average BMI was slightly higher I think it was in the high 20s average age was I think up in the mid 50s it was a higher age group where you'd expect some effects so they proved at least what we had seen in mice that you can get nad to rise beyond the liver”