Tamoxifen
Tamoxifen is an antagonist of the estrogen receptor in breast tissue. It has been the standard endocrine (anti-estrogen) therapy for hormone-positive early breast cancer in post-menopausal women, although aromatase inhibitors have been proposed.
Some breast cancer cells require estrogen to grow. Estrogen binds to and activates the estrogen receptor in these cells. Tamoxifen is metabolized into compounds that also bind to the estrogen receptor but do not activate it. Because of this competitive antagonism, tamoxifen acts like a key broken off in the lock that prevents any other key from being inserted, preventing estrogen from binding to its receptor. Hence breast cancer cell growth is blocked.
Tamoxifen was discovered by ICI Pharmaceuticals (now AstraZeneca) and is sold under the trade names Nolvadex, Istubal, and Valodex. However, the drug, even before its patent expiration, was and still is widely referred to by its generic name "tamoxifen."
Human chorionic gonadotropin (HCG)
Human chorionic gonadotropin or Human chorionic gonadotrophin (hCG) is a glycoprotein hormone produced in pregnancy that is made by the developing embryo after conception and later by the syncytiotrophoblast (part of the placenta)
Anabolic steroid adjunct
In the world of performance enhancing drugs, hCG is increasingly used in combination with various anabolic androgenic steroid (AAS) cycles. As a result, hCG is included in some sports' illegal drug lists.
When AAS are put into a male body, the body's natural negative-feedback loops cause the body to shut down its own production of testosterone via shutdown of the hypothalamic-pituitary-gonadal axis (HPGA). This causes testicular atrophy, among other things. hCG is commonly used during and after steroid cycles to maintain and restore testicular size as well as normal testosterone production.
High levels of AASs, that mimic the body's natural testosterone, trigger the hypothalamus to shut down its production of gonadotropin-releasing hormone (GnRH) from the hypothalamus. Without GnRH, the pituitary gland stops releasing luteinizing hormone (LH). LH normally travels from the pituitary via the blood stream to the testes, where it triggers the production and release of testosterone. Without LH, the testes shut down their production of testosterone. In males, hCG helps restore and maintain testosterone production in the testes by mimicking LH and triggering the production and release of testosterone.
If hCG is used for too long and in too high a dose, the resulting rise in natural testosterone will eventually inhibit its own production via negative feedback on the hypothalamus and pituitary gland.
Weight loss
A controversial usage of hCG is as an adjunct to the British endocrinologist A.T.W. Simeons' ultra-low-calorie weight-loss diet. Simeons, while studying pregnant women in India on a calorie-deficient diet, and “fat boys” with pituitary problems (Frölich's_syndrome) treated with low-dose hCG, discovered that both lost fat rather than lean (muscle) tissue. He reasoned that hCG must be programming the hypothalamus to do this in the former cases in order to protect the developing fetus by promoting mobilization and consumption of abnormal, excessive adipose deposits. Simeons, practicing at Salvator Mundi International Hospital in Rome, Italy, recommended low-dose daily hCG injections (125 mg) in combination with a customized ultra-low-calorie (500 cal/day, high-protein, low-carbohydrate/fat) diet loss of adipose tissue without loss of lean tissue. After Simeons’ death, the diet started to spread to specialized centers and via popularization by such as the author Kevin Trudeau, a specialist in promotion.
