While most women don’t care about the size of a man’s penis, this can be a touchy issue with men. The good news is that low testosterone in older males does not necessarily affect penis size. As a young man goes through puberty, his testosterone levels at that time will affect the size of his penis.
Low testosterone levels in older males will usually cause other sexually-related side-effects such as sexual performance, decreased libido or an inability to maintain an erection. These side effects can be treated with testosterone therapy.