The side effects of Proviron will include the suppression of natural testosterone production, but it’s not as cut and dry compared to many steroids . The use of anabolic steroids, any anabolic steroid will suppress natural production; however, the rate of suppression varies greatly from one steroid to the next. In the case of Mesterolone, the total rate of suppression can be so minimal it can be insignificant. With standard Proviron doses, which normally fall in the 50-150mg per day range, the total suppression of natural testosterone production should be minimal of relatively no concern. When the dose surpasses the 150mg mark this will create a greater level of suppression, but there is no reason for any man to need a dose greater than 150mg per day. In theory, assuming your natural testosterone levels are in the high end optimal range, the individual could implement a cycle of Proviron and a moderate suppressive steroid at a low dose such as Anavar and forgo the need of exogenous testosterone supplementation. However, the Anavar dose would need to be very low and natural levels very high. Most men will still need exogenous testosterone, especially when we consider standard anabolic steroid cycles .