I've used it. I got the best certified quality of PT-141. However, I believe I am in the group of non-responders. I know the purity of the peptide is high, because I get the initial symptoms. About 5 minutes after you inject it subq, you get a flush in your face and neck that lasts for about an hour, hour and a half. Also heart rate is slightly increased, as well as blood pressure.
PT-141 is not supposed to act similar to Viagra. Viagra promotes blood flow to your cawk. PT-141, acts in the brain, and is supposed to give you the desire for sex, after about 4 hours of injection.
I have not done enough research on myself, however, I could probably say that the next morning, the morning wood is harder and longer lasting. But still, not 100% sure; could be coincidence.
Also the peptide lasts a long time in the refrigerator. I tried it again after about 2 months seating there, and had the same potency and effects.