You must have certainly received one of those spam emails or have seen that “weird trick” ads about achieving those super human skills on bed and leading a great happy life with your sexual partner. Truth is not all of those companies are out of legal purview of USA but then why not FDA going after such companies?
There are many legit products( read VigRx Plus reviews for example) in this industry as well. But,it is very hard to separate those from non-legit ones.
It is not that FDA is not doing their job. But,the action is not clearly enough.
You can track about FDA notifications here.