I used PT-141. It worked great for libido and hardness and duration of erection. You do get a face flushing right after the injection. It's not unpleasant. It takes several hours to "kick in" but seems to last for a couple of days. Beware: I did get previously unnoticeable moles, large ones called epidural nevus appear on my buttocks. They have faded somewhat but are still noticeable after 3 - 4 YEARS. The only way to remove them is with CO2 laser. Expensive and painful. So be careful with this stuff. I did do this stuff several times in a row. Like once or twice a week for a month when this happened. Maybe more limited use or lower dose (0.5mg) might be better. I had skin color changes (darkening) in my lower legs too.