@feruze-- I happen to believe that there is no such thing as a safe steroid. The article did a great job of mentioning that the damage caused by steroid use is not diagnosed until many years after.
I've also seen studies about mesterolone and quite a few of them state that "no kidney damage" was found following these studies. I think this is really funny. Of course, there will be no apparent damage so soon after the use of a steroid. A lot more time needs to pass and these studies need to get back in touch with the participants and test them again for any damage.
I think all steroids, including mesterolone, should be used with utmost caution. In fact, they shouldn't be used unless it's completely necessary. I understand that you were trying to treat a medical condition which is fine. But using steroids simply for libido function or to aid in body building is just way too risky in my opinion.