I purchased the sd muscle stack along with the tr system; haven't taken it yet but i doubt that you should start feel anything that soon, patience, you will, given your calorie intake is right and you got all the right support supplements, give it a week or two then you should be of some concern i believe if nothing is happening. just go about your normal excercising and supplementation and you should be good, homie. If all else fails and your not satified if it was purchased from pp and that was your first purchase they'll refung you for your product after sending it back to them