The most effective medication for ED is no longer available in the UK for that purpose, Papaverine. It worked where others failed and was not primarily for ED but very effective. Once you got over the issue of injecting yourself in the penis it was almost instant and a rock solid erection would last an hour minimum, usually an hour and a half. No recovery time after ejaculation, just keep on going. It is however liable to cause Priapism, if misused, where the erection fails to subside for hours and can lead to hospitalisation. I think this is why it was withdrawn. It is still available in other countries, Australia and the US. It also seems effective when included with other chemicals in a trio of chemicals which are supposed to lesson the unwanted side effects but again not available here.