I asked this question before and was told "B-12 shots". but I`m not gonna stick myself just yet. So I`m taking B-12 capsules. I don`t know if they`re the same I highly doubt it, but they can`t hurt for energy.
Actually, my response was for the thread orginator.
As far as GHB goes, I don't really know much about it. I believe it's used either as a recreational drug or to induce deep restful sleep. (Which is benefitial to recovery.) But, I haven't ever heard of it increasing appetite.