I was too busy these days.Thank you all for the suggestions, I'll look into it.
I'm thinking Benfotiamine(+thiamine) + the rest suggestions of the b complex + choline + carnitine and arginine.I'll check the dosages and post a stack the next days.
I have BCAA but no way he will take the unflavored powder, so I will leave it out for now.Sam-e also, due to its price.I'll try it last.
I'll download an app to his mobile to make sure he is taking everything every day.I hope he sees some improvement in the first couple of weeks because he is not very fond of supplements.
Please keep the thread going, if you have any other ideas.I think it's a common problem.