The abnormal enlargement of male breasts, in a way that resembles to female ones is called gynecomastia. It is a rather common condition that afflicts men of all ages; babies or young boys in puberty, adolescents and adults with some health problems. According to the experts the main cause of genuine gynecomastia is the imbalance in hormones, which can occur from liver or thyroid problems, numerous health conditions, but also from use of certain drugs that men can take in order to deal with other problems they might have. These drugs can be legal or not, prescribed by physicians or over the counter products.

Not all drugs and oral medication act the same way or produce the same results; as we know hardly two people can have the exact same problems when taking the same medication, as it all depends on the physiology and health condition of the individual. In any case, though, doctors know that there are particular types of drugs that can cause gynecomastia as a side effect, and usually prepare their patients for this possibility. Patients should not avoid or omit them, because not all drugs have the same side effects; it mainly depends on a vast array of factors.

Tricyclic antidepressants, valium and diazepam used by people with depression or psychotic behavior, anti-androgen such cyproterone, flutamide and finasteride and chemotherapy undergone by men with prostate cancer can affect the hormones in blood; estrogen and testosterone levels differentiate, causing gynecomastia. The vast majority of men suffering from gynecomastia from these drugs are over 40 years of age.

Among the known substances that cause gynecomastia are anabolic steroids and androgens. In fact this is the most common side effects of these substances, as it can occur to athletes, body builders and individuals who undergo one or more cycles of anabolic steroid use. Amphetamines and other similar pills can also affect the development of breasts in men of all ages. This is actually the most common cause of gynecomastia in younger men.

Medication and substances described above can upset the balance of hormones in blood. Men with certain health issues can show increased levels of estrogen and low levels of testosterone; these hormones are used to adjust the gender characteristics in any individual, thus, their imbalance can cause a series of side effects, among which is gynecomastia and development of female traits.