Drugs & Medication

Progestagens (also spelled progestogens or gestagens) are hormones which produce effects similar to progesterone, the only natural progestagen. All other progestogens are synthetic and are often referred to as progestins.

All progestagens have antiestrogenic (counteracting the effects of estrogens on the body) and antigonadotropic (inhibiting the production of sex steroids by gonads) properties.

Progestogens differ in their potency (affinity for progesterone receptors) and side effects. Such side effects may be androgenic (medroxyprogesterone and most C19 progestagens), antiandrogenic (cyproterone acetate), estrogenic, glucocorticoid (some C21 progestogens) or antimineralocorticoid (progesterone).

There is a difference between natural progesterone and all other synthetic progestagens. Because natural progesterone cannot be patented drug companies have slightly altered the natural progesterone or attached various side groups to the the basic natural progesterone molecule in order to allow them to patent their version.

Numerous studies on HRT were completed prior to the Women's Health Initiative (see external links) and some demonstrated that estrogens plus progestagens, while reducing the risk of endometrial cancer, actually increased the incidence of breast cancers.

There is substantial controversy regarding the safety and effectiveness of artificial intake of hormones. While the synthetic versions of progesterone that are marketed by drug companies have all been tested over many years by the FDA and other world-wide government bodies and are acceptably safe, recent events with drugs such as Bextra, Celebrex and Vioxx have shown that some drugs may need to be withdrawn after the FDA has become aware of doubts about their safety. This has not been the case with synthetic progestagens, which billions of women have taken for many decades in various forms. Some interested parties have threatened legal action against those individuals who claim otherwise.

Uses

• Birth control
  • Most progestogens are used for their antiestrogenic properties in oral contraceptives to avoid overstimulation of the endometrium which could lead to endometriosis and cancer.
  • Medroxyprogesterone acetate (brand name Depo Provera) is used by depot injection.
  • Etonogestrol is released by subcutaneous implants (Implanon®). Similar products (Norplant® and Jadelle® contain levonogestrol.
• Antiandrogen
  • E.g. Cyproterone.

External links

• The Million Women Study
• The Women's HOPE Study (PubMed Abstract)
• HERS Study (JAMA Abstract)