There are no words to describe how fantastic this product is. I have suffered from chronic fatigue syndrome (similar to ME) for two years. I have tried several different versions of NADH and B3 (NADH is the coenzyme version of B3), and the Professor Birkmayer NADH really is the only one that works. In terms of reducing my fatigue and giving me energy, this NADH really is terrific, so effective in fact that I am likely to continue taking it after I am fully recovered from chronic fatigue because it is so massively important in creating energy in all our cells (actually in the mitochondria which are the energy factories in our cells). Everything that the Finchley Clinic say in describing this product is correct - and then some. I cannot rate this product highly enough!