Progestogens (natural) creams for postmenopausal women

• these are derived from diosgenin, a plant sterol that can be extracted from several plant sources, including yam and soya. Natural progesterone, unlike synthetic progestogens, is identical in structure to the hormone produced by the human placenta and corpus luteum (the structural similarity and source of the progesterone are the basis for the claims that these creams are 'natural')
  
  
• in women with normal menstrual cycles plasma progesterone levels vary during the cycle (follicular phase below 4 nmol/l, median levels during the luteal phase is about 15 nmol/l, peak day-21 levels are 35-45 nmol/l. There is little data on plasma levels and absorption from topically applied 'natural' progesterone creams but it seems unlikely that these creams can provide physiologically adequate plasma progesterone levels (1); also it seems unlikely that 'natural' progesterone creams available could deliver enough progesterone to adequately oppose oestrogenic stimulation of the endometrium by exogenous oestrogen (2)
  
  
• A Drug and Therapeutics Bulletin review concerning natural progesterone creams in postmenopausal women concludes that (2):
  • there is limited evidence that these creams may lead to an improvement in vasomotor symptoms in some postmenopausal women
  • there is no convincing evidence that the use of these creams can prevent bone loss in postmenopausal women
  • the plasma levels of progesterone achieved via use of the creams appear insufficient to oppose oestrogenic stimulation of the endometrium by exogenous oestrogen - therefore these natural progesterone creams should not be used as an alternative to synthetic progestogens, in attempt to protect against treatment - induced endometrial hyperplasia and cancer

Using natural progesterone cream for postmenopausal therapy regimens should be considered as an unsubstantiated treatment option, and its clinical applications must be restricted to well-designed interventional trials that assess its efficacy and safety (3)

Reference:

• (1) Cooper A et al (1998). Systemic absorption of progesterone from Progest cream in postmenopausal women. Lancet, 351, 1255-6 (letter).
• (2) Drug and Therapeutics Bulletin (2001), 39 (2), 9-11
• (3) Elshafie MA1, Ewies AA.Transdermal natural progesterone cream for postmenopausal women: inconsistent data and complex pharmacokinetics..J Obstet Gynaecol. 2007 Oct;27(7):655-9.