Technische Universität München

The Entrepreneurial University

Exogenous supplementation of testosterone is associated with an increasing level of estrogen produced in the body during the process of aromatisation. Elevated blood levels of testosterone and estrogen trigger a regulation mechanism which lower testosterone production, decrease aromatization rate and stabilize estrogens at physiological levels. Prolonged elevation of estrogen levels could lead to a loss of muscle mass, gains in fat and general feminisation of the body.
Aromatase inhibitors, selective estrogen receptor modulators and other anti-estrogenic substances might be considered to be profitable to mask side effects of anabolic-androgenic steroids abuse.
Estrogen exhibits potent effects on the central nervous system modulating noradrenergic, dopaminergic, and cholinergic systems. The stimulatory effects of estrogen and inhibitory effects of anti-estrogenic substances on the central nervous system modify feeling of energy and libido of a person. Unspecific side effects of the medical treatment with hormone antagonists and modulators on the central nervous system are headaches, hot flushes and an impaired vision.