Natural progesterone

Progestogens have a high affinity for sex hormone-binding globulin. Natural progesterone is rapidly metabolized in liver and can therefore not be given orally. In oral contraceptives synthetic... 

Lightman A, Kol S, Itskovitz-Eldor J. A prospective randomized study comparing intramuscular with intravaginal natural progesterone in programmed thaw cycles. Hum Reprod 1999 14(10) 2596-9. 

When used alone, estrogen replacement therapy increases the risk of endometrial cancer. This risk can be eliminated by treatment with a progestational agent for up to 14 days a month. However, the oral administration of natural progesterone has associated limitations ... 

Due to the unique biological similarity of drospirenone (e.g., mild anti-aldosterone and anti-androgenic activity) to the natural progesterone, Yasmin has important advantages over the known oral contraceptives [14]. For example, the use of Yasmin does not initially cause any increase in body weight, and it is also effective in treating mild to moderate acne. Likewise, menstrual cycle control is excellent. 

Darj E, Axelsson O, Carlstrom K, etal. (1993) Liver metabolism during treatment with oestradiol and natural progesterone. Gynecol Endocrinol 7 ... 

Natural progesterone, A -pregnene-3,20-dione, has the structure expressed by formula (296). Its antipode (297, 298) must be named by the existing rules of nomenclature as "8a, 9)8,10j3,13a, 14jS,17Q -A -pregnene-3,20-dione. This name is not only difficult to understand but it is completely unsuitable for use since no name is left for the racemic compound it can be described only by a combination of the names of the two enantiomers. Consequently, it is natural that with the development of work on the total synthesis of steroids much attention has been devoted to the question of nomenclature. 

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