[Significance of progestins in treatment of endometriosis].

Endometriosis is a chronic benign proliferative disease with high risk of recurrences, despite of medical and/or surgical treatment. The variation and severity of symptoms reduce the quality of life, the ability of working and the sexual behaviour. Medical cure of symptoms is a central concept in the therapeutic strategy. Low dose progestins have shown to be effective in the clinical routine since several decades although scientific data are rare and insufficient about the mechanism of action of these substances. Subjective and biochemical side effects are important for the choice of a specific progestin. The dosage is dependent of the biological activity of the drug, especially the effect on the endometrium. On the endometriotic implants and cysts high dose therapy with progestins induces the same regressive changes as complete estrogen deprivation by reversible "medical castration".