Gynecomastia, a condition where the breast tissue of adolescent boys or adult men becomes enlarged and sometimes tender or sore, can be an uncomfortable and embarrassing problem, but treatment with the estrogen-blocking drug tamoxifen can help. Though the primary use of this medication is for the treatment of breast cancer, several studies have shown positive results when using tamoxifen for gynecomastia. It can be helpful in a variety of situations that lead to the condition, including hormonal changes during puberty, anti-androgen treatment for prostate cancer, and in men for whom the issue has no known cause. Tamoxifen is also known to help men who take anabolic steroid cycles to increase muscle mass avoid gynecomastia from the hormonal changes caused by the steroids. It is most effective for treating the condition before it occurs, or when it has only been present for a few months.
Tamoxifen has traditionally been used to treat certain types of breast cancer. The drug does this by blocking the effects of estrogen, which can encourage some tumors to grow. Since gynecomastia typically results from excess estrogen in a man's body, tamoxifen can also help prevent or treat the condition by blocking the hormone's effects.
There are several scenarios where taking tamoxifen for gynecomastia is known to be helpful. Adolescent boys who develop the problem during puberty may be given the drug if the condition does not resolve itself quickly or causes severe emotional distress for the patient. Men undergoing prostate cancer treatment involving anti-androgen therapy may take tamoxifen to prevent the breast enlargement it usually causes. Those with idiopathic gynecomastia, where no cause for the condition is apparent, may also choose the drug, particularly if it persists for several months or causes discomfort.
Bodybuilders or other athletes who take anabolic steroids sometimes use tamoxifen for gynecomastia. The elevated estrogen levels that occur after a cycle of steroids ends puts the men using them at risk for gynecomastia. Taking tamoxifen has been known to help prevent this issue.
While taking tamoxifen for gynecomastia has typically been found to be quite successful, it is important to note that it typically needs to be taken at the right times to be most effective. It works best as a preventive measure, or before the breast tissue has been enlarged for too long, typically within a few months of development. Once the condition has been present for a year or more, positive results from taking tamoxifen decrease significantly.