I had minor positive effects, using a moderate dose of 5mg.
I've tried Seeking Health's sublingual NADH (25mg) + CoQ10 (50mg) but gives me an horrid headache, every time. Don't know if it's one of the active ingredient or one of the excipient... the lemon-like flavor is a bit strong for my taste...
My experience:
I came across NADH since it is supposed to increase BH4 levels (BH4 supplementation helps me a lot but is difficult to get and expensive, see threads here in the forum).
Took the Seeking Health product 25mg NADH sublingual regularely with no negative effects but also noted no positive effects (Which does not mean it has no benefints because my MS/CFS-like symptomes where gone before that try so caffeine like benefits as described regularely I would not notice because nowadays I usually wake up fresh anyway for a couple of months. So maybe it helps me but not noticeable).
Then I tried a stronger product from Vitabay with 50mg NADH sublingual. I got a horrible headache stronger than I have ever experienced before, I was really desperate, now I know how Migrane must feel like. I am usually in the lucky situation to have headache hardly ever (maybe five times a year a light headache, usually due to muscle tension in the neck when detoxing wich DMSA), Migrane I never have experienced before.
I am just wondering if NADH ist the wrong supplement for me (I do not need it) or it triggered some positive reaction? Some write that Niacin (NADH precursor) is generally important for detox (e.g. Cytochrome P450) and in particular it is supposed to open fat-cells for releasing toxines.
just my 2cents