When taken as prescribed for you, testosterone therapy is generally regarded as safe. However, as with any prescription medication, there are some possible side effects to testosterone therapy. Though rare, testosterone therapy side effects can include:
Increased body hair
Enlarged breasts
Headache
Increased anxiety
Numbness (patches and gels)
Pain or inflammation of the injection site (injections)
However, most, if not all, of these possible side effects of testosterone therapy can be avoided by following your doctor’s instructions.