Anti-estrogen drugs that prohibits the production of estrogen that might build during and after a heavy androgenic cycle.
Testosterone is the primary substrate used in the male body for the synthesis of estrogen, the principal female sex hormone. In the context of the average healthy male, the amount of estrogen produced is generally not very significant to one’s body disposition, and may even be beneficial in terms of cholesterol values. However, in larger amounts it does have potential to cause many unwanted effects including water retention, female breast tissue development (gynecomastia), and body fat accumulation. For these reasons, many focus on minimizing the build-up or activity of estrogen in the body with aromatase inhibitors such as Arimidex or anti-estrogens such as Clomid or Nolvadex, particularly at times when gynecomastia is a worry or the athlete is attempting to increase muscle definition.
PCT(Post Cycle Therapy) is a period of medication treatment that follows the use of anabolic steroids that combine beneficial effects of drugs mentioned above.