Before delving into this subject, I’d like to say first and foremost, that in users of anabolic /androgenic steroids (AAS) the first step in combating the development of gynecomastia, or male breast enlargement, is to eliminate the causative agent: the anabolic steroid. Drug-induced gynecomastia almost invariably resolves on its own when a person quits taking the drugs responsible for it, if caught before permanent fibrosis develops.
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In truth, the etiology of gynecomastia is unknown and a number of agents including estrogens, progestins, GH, IGF-1, and prolactin may be involved. However, most authorities believe that a decreased (T+DHT)/E ratio is central to the development of gyno, and that blocking the effects of estrogen, or increasing T + DHT levels, is central to ameliorating the problem.