Muscle Gain and Testosterone: Is the Connect Real? Plus, real-life Supplementation Insights

I have had this question pricking me for a long time. Most of the online reviews I read about bodybuilding or exercising with religious passion talk about how Testosterone is vital for gaining muscle mass, i.e. men and women!! Some blogs go on to preach that female bodybuilders and athletes use Testosterone supplementation to gain chiselled physiques. I recall getting my Testosterone levels checked once, about two years back. The results were not shocking, i.e. I was just beyond the mid-range, so I am neither deficient nor loaded with Testosterone. Does this mean I have an average chance to gain muscle? Are my hormones controlling the degree of gym gains I make?? I have felt the androgenic and boosting results of taking light testosterone supplements.