Common side effects of depo-testosterone, or testosterone cypionate, include acne, nausea, depression, headache, anxiety and localized pain, according to RxList. In addition, some patients undergoing testosterone cypionate treatment experience gynecomastia, increased erection frequency and duration, and oligospermia.
Testosterone cypionate treats testosterone deficiency in men and boys, explains RxList. A lack of the naturally occuring hormone can cause delayed puberty, impotence and other hormonal imbalances. Women use testosterone cypionate to treat breast cancer that has spread to other parts of the body. Dosage varies by age, sex and diagnosis. Treatment can interact with blood thinners, diabetes medication, insulin and steroids. Treatment can harm unborn fetuses.