Dissapointed with bigtrea 1.5% have tried bigtrea 1.5% because i have heard it is the best of Bigtrea series. Frist 3-4 times i could feel stimulation and energy for the two hours and rest 3 hours i could feel very nice realaxation, optimistic thoughts, anxiety relief, social phobia decrease. After 3-4 days i do not feel stimulation at all. No matter how much i take. I feel something which is hard to describe. Something between sadness and relaxation. Taste is great. It is not bitter at all.