The Mayo Clinic does not support testosterone for muscle and joint health. I quote:

However, many professional societies, including the International Menopause Society, support careful, monitored testosterone use in postmenopausal women to improve their sexual desire, as long as there are no other contributing medical or psychiatric conditions. The goal of treatment in these women is to get their testosterone up to the levels that are seen in younger women before menopause. Despite what many women and the media tout, testosterone use is not recommended for:

Treating depression
Improving bone density
Improving muscle mass or strength
Reducing body fat
Enhancing general well-being
Improving cognition