the proof for me was that i have had 3 attempts at growing feminised white widowand 3 time the bitch turned hermie on me, then my good freind mobay sent me bottle of thrive in one of his numerous generous acts of freindship , i used it on the widow and low and behold the perfect grow, no stress bigger yeild and an over all healthy looking plant, now it is an esential part of my grow , so anyone who hasnt tryed it , should as it really does work, the postman.