hi testosterone definitely has an effect on sperm count and can both lower count and cause a 0 count. there is often improvement after stopping testosterone it usually takes at least 3 months to see improvement and the longer he has been on it the longer it can take to show improvement. the issue with synthetic testosterone is that it causes the male body to think it is producing enough testosterone when it really isn't. therefore it slows some of the other hormones that make sperm production happen this in turn lowers actual sperm production. but then it would depend just why your on them was it because it was just low? was it because your get weak erections? if it was this last one then its a loaded gun but a drug called clomid could help you there. do see your doctor or uro for far more info. good luck
i am 48 and been on testosterone since 2006. this has caused me to be infertile. what are chances this can be reversed.