I was reading this paper on routes of drug administration and noticed that it mentioned intravaginal drug administration. It looks like this is a good way to take drugs because there are a lot of blood vessels which means you absorb a lot of the drug and you bypass the first-pass metabolism effect which catabolizes a lot of the drug before it gets to your liver.
I noticed there’s no mention of penile drug administration. Would there be any advantage of taking drugs this way, either by insufflation into the urethra or by injection into the penis? I googled it and it sounds like there are no drugs that are administered this way except for penile injections - similar to Botox, but for your penis, and not used for absorption purposes.