Common side effects from testosterone medication include acne, swelling, and breast enlargement in males. Serious side effects may include liver toxicity, heart disease, and behavioral changes. Women and children who are exposed may develop virilization. It is recommended that individuals with prostate cancer not use the medication. It can cause harm if used during pregnancy or breastfeeding.
Some of these signs and symptoms can be caused by various underlying factors, including medication side effects, obstructive sleep apnea, thyroid problems, diabetes and depression. It's also possible that these conditions may be the cause of low testosterone levels, and treatment of these problems may cause testosterone levels to rise. A blood test is the only way to diagnose a low testosterone level.