My wife and I were anxious to try the P and O shot that Dr Robinson was offering. Now I can't tell you with total certainty if it was the P/O shot or the hormone therapy we've initiated as well - but I can tell you we both feel like our sex lives are 100% different since doing both! Personally speaking I have noticed an increase in girth, not sure about the length but it just feels more like my young self. We're ready to try round 2, its been about a year since the first P-shot and I'm confident enough about the whole procedure that I'd like to continue with more treatments.