If you want to see if NAD+ will work on you, befote trying a more expensive infusion, I'd get some NAD+ from either Alive by Nature or LIAS Research and see how they work. You might try a relatively small dose, like 25-62mg and see what they do.
From the articles I've read too high an NADH/NAD+ ratio is bad. Therefore, using NAD+ may correct the ratio and taking NADH may worsen it. This is my theory, don't know for sure.
The military high dose NAD+ protocol was developed to get people over the hump of getting off additive substances. That's not us, so if you're doctor suggests something like that with 500-1500mg infusions over a few days, I believe it would be a mistake.
For one thing, IV NAD+ is a difficult IV. I get 200mg once every 7-10 days, along with a mito cocktail of other mito nutrients, and we have had to add in the NAD+ at the end for me to tolerate it. When the NAD+ is added, it hypes up my system, particularly my digestive system, and I get nauseous and my bowels want to empty pretty soon. Limiting the timeframe this is going on is desirable, and a lot of the time, I need benadryl to keep from vomiting. We have to slow the drip rate down also, which reducrs the nausea. So, I cannot imagine going to 2-5 times as much in a session - I just couldn't tolerate it.
Even with these difficult symptoms, which pass quickly after the NAD+ is done, and I get glutathione as a follow-up, the effect of the NAD+ IV is much better than the oral. From the beginning, it made me feel like an almost normal person for about 36 hours. Over time, doing the IV NAD+ every 7-10 days, with 125mg sublingual NMN or NAD+ on the days in between, has greatly helped to normalize my life.
Another reason I wouldn't go higher is I'm a cancer survivor and too much NAD may feed cancer if its lurking about. I think the biohackers doing more are running a big risk., so I try to take just enough to help.
NMN made me jittery at first but these days, it works interchangeably with NAD+. I figure gorcing my body to convert NMN to NAD+ is useful rather than just giving the end ingredient.
One other thing you might ask your doctor about is doing AMP IVs. My doctor said hes seen them be very helpful for patients but wasn't able to source it. (Adenosine Monophosphate is a precursor of Adenosine Triphosphate, ATP, our body's energy currency.)
Why is your doctor suggesting NAD+? Does he/she suspect toxicity or just think you lack enough? Have you looked into peroxynitrites, arsenic toxicity, or mold toxicity? Or repairing. damaged membrsnes with NT Factor or phospatidyl choline? Have you done a MitoSwab test, or taken carnitine, B2, MitoQ PQQ, B vitamins or BCAAs? I think NAD is best as part of a comprehensive program - it's not a magic bullet though it can dramatically help over time.