
Originally Posted by
MuscleInk
Great question!
Any exogenous testosterone (TRT or anabolic use) will suppress intratesticular testosterone production which in turn often leads to azoospermia and in some cases, severe oligozoospermia. HCG (used during cycles) and SERMs (used post cycle) - clomiphene citrate in particular - can provide rescue and restorative effects on testicular function, spermatogenesis, and sperm motility. Unlike SERMs, aromatase inhibitors may actually impair normal testicular function and thus, are NOT recommended during PCT when restarting intratesticular function is the desired clinical outcome. It is believed HGH may offer some benefits as well but clinical data are as yet incomplete.
There are many mechanisms by which sperm integrity or fertility may be compromised by exogenous testosterone including increased apoptosis, protamine deficiencies, and abnormal chromatin maturation. The likelihood of these impairments increase with length of cycles, frequency of anabolic use, age, diet, and exercise.
Having said this, many men who use anabolics or receive TRT remain fertile. The key is moderation, responsible use, and when indicated, use of HCG and clomid to aid in restarting intratesticular function.