I am wondering about what exactly constitutes priapism. I find Invicorp to be quite long lasting. Last time I tried it, I injected about half the dose and it lasted over two hours. It did then start to go down, but very slowly. At at about three and a half hours it was maybe at 1/4 or 1/5. It wasn't until a little after four hours that it was completely back to normal. Looking at medical sites on the web, some suggest that it is only really a full, rigid erection beyond four hours that counts as priapism. Others suggest that any amount of sustained rigidity can be dangerous. I will ask about it at my next appointment with andrology, but that's not until October. In the meantime, if anyone has any advice I'd be grateful to hear it!