I've been using phenibut off and on for almost 100g worth, but haven't yet built up tolerance because I've been avoiding it by only using it around twice per week at 1-1.5g each time. Euphoria seems to be best if dosed half at bedtime and half in the morning, but I've been using L-Theanine, Piracetam, Alpha-GPC, and Rhodiola Rosea along with it. From what I can tell, euphoria is increased with the addition of at least Theanine especially.
Question is... how much can the tolerance development be counteracted by the addition of these types of "support" supplements? I know the euphoria feeling can be "renewed" with these additions, but perhaps phenibut can be successfully used up to maybe 4 times a week without real tolerance development if enough Theanine and RR are used?