There is Trestolone which is studied and shown to be very effective (patients had zero sperm in their ejaculate after several months of administering the compound), but there are hormonal side effects similar to testosterone, which kind of explains why it's pretty much only used in the bodybuilding community.
The pill in the article is a non-hormonal one, which is interesting
The pill in the article is a non-hormonal one, which is interesting