I was reticent to begin with, but determined to persevere. You know how it is ... Difficult to know if something is working or not, or whether there is a placebo effect or something.
But after about a month and a half, it really kicked in and muscle began to develop more noticeably, with weight reducing also (but I didn't need to lose much anyway).
Works best with regular exercise, be it gentle or intensive (increase the dose of you do intensive training.
Take it 20 minutes after you finish (walking, running, dancing, fitness training, whatever).
Take a regular dose even if you don't exercise.
Beware - You do get muscle aches like with intensive sports activities ! But, well, that's part of the muscle-building deal :-)