I have been using a ring while I sleep for a while now. Before I attempted this I tested as closely as I could to the conditions I thought likely to be generated in sleep. I got repeated erections without physical stimulation and then lost the erection while wearing the ring continuously. I progressively increased the time I tested this until I was past the 4 hours mark and many gained and lost erections without issue, at that point I used it while I slept once. There were, and are, no issues presented the next morning and my EQ has only progressively gone up.
I do not know why you would need viagra or cialis unless you do not naturally get nocturnal erections. If that is the case see a doctor please.
It is worth noting that the vascularity of my penis is getting notedly more pronounced and if you wish to avoid making your veins bigger you should not do this or any other form of prolonged clamping/cockring. I am already in the 6” girth range and gains in that department are now difficult to get so I decided to try this as safely as I could. Have only gained .2” since starting this which just as easily could come down to natural variation.