If you're anal about it, try to avoid the following chemicals:
Estrogen blockers are chemicals that stop estrogen from carrying out its role in specific bodily functions. There are several types of estrogen blockers: aromatase inhibitors, antiestrogens, and specific estrogen receptor modulators. Aromatase inhibitors actually prevent the production of new estrogen. Antiestrogens and specific estrogen receptor modulators block estrogen receptors, so that the hormone cannot bind itself to certain body parts. Your doctor can prescribe this to you in the form of a pill or a monthly shot to be given in a doctor's office.
In addition to the belief that estrogen blockers for men increase muscle mass and strength, research suggests these substances may play a role in preventing male hair loss. A study using lab mice suggests that it is the presence of estrogen rather than the lack of male hormones that may lead to hair loss. As men age, it is natural for estrogen levels to rise, which may be a factor in age-related balding. Other factors that may cause an increase in estrogen in men include alcohol consumption and obesity. Many suspect that hormone mimicking chemicals in the environment also raise estrogen levels.