The references quoted on each of the research pages are presented in reverse chronological order, so the most recent research can be seen at the top of the list.  Some significant, recently published clinical studies are also quoted below.

• Wright DW, Kellermann AL, Hertzberg VS, Clark PL, Frankel M, Goldstein FC, Salomone JP, Dent LL, Harris OA, Ander DS, Lowery DW, Patel MM, Denson DD, Gordon AB, Wald MM, Gupta S, Hoffman SW, Stein DG.  ProTECT: a randomized clinical trial of progesterone for acute traumatic brain injury.  Ann Emerg Med 2006 Sep 28; [Epub ahead of print]. 
  
  A neuroprotective effect of progesterone was observed in this randomized, placebo-controlled trial of very high dose, intravenous progesterone therapy given for 3 days after acute traumatic brain injury.  Only 13% of the patients died within 30 days after injury in the progesterone group, compared with 30% of the placebo group, and the progesterone group was more likely to have a moderate to good functional outcome after 30 days than the placebo group.  Even at the extremely high dose used, no serious adverse events were seen with progesterone.
  
  
• Ho JY, Chen MJ, Sheu WH, Yi YC, Tsai AC, Guu HF, Ho ES.  Differential effects of oral conjugated equine estrogen and transdermal estrogen on atherosclerotic vascular disease risk markers and endothelial function in healthy postmenopausal women.  Hum Reprod 2006; 21(10):2715-20. 
  
  In this comparison of 0.625 mg/day oral conjugated equine estrogen (CEE) versus 0.6 mg/day 17β-estradiol transdermal gel for 6 months or no treatment, the oral CEE group showed significantly increased levels of C-reactive protein (CRP), a marker of inflammation, while the transdermal and control groups showed no increase in CRP.  The transdermal estradiol group showed a similar beneficial effect on flow-mediated vasodilation in the brachial artery to the CEE group, indicating a comparative therapeutic benefit but without increasing the risk of atherosclerosis.
   
• Fournier A, Berrino F, Riboli E, Avenel V, Clavel-Chapelon F.  Breast cancer risk in relation to different types of hormone replacement therapy in the E3N-EPIC cohort.  Int J Cancer 2005; 114(3):448-54. 
  
  Combined hormone therapy with estrogen (either oral or transdermal) and synthetic progestins was found to carry a significantly increased risk of breast cancer compared with estrogens plus oral micronized progesterone in this large cohort of postmenopausal women.  In fact, no increase in breast cancer risk was seen in the estrogen plus oral micronized progesterone group compared with estrogen alone.  This large multicenter study therefore suggests that there is a dramatic difference between the effects of bioidentical progesterone versus synthetic progestins on breast cancer risk.
  
  
  
• Leonetti HB, Landes J, Steinberg D, Anasti JN.  Topical progesterone cream as an alternative progestin in hormone therapy.  Altern Ther Health Med 2005; 11(6):36-38. 
  
  This study evaluated the endometrial effects and determined patients' acceptance of transdermal progesterone cream compared to standard hormone therapy.  Healthy menopausal women were recruited and received a pretreatment endometrial biopsy (EMB). They were randomized to 0.625 mg conjugated equine estrogen (CEE) daily and 2.5 mg medroxyprogesterone acetate (MPA) (PremproTM) or daily 0.625 mg CEE and twice daily 20 mg transdermal PC (Pro-gest®). At the end of 6 months, a repeat EMB was obtained, and the women were crossed over to other treatment. A final EMB was performed after the final 6 months.  Twenty-six women completed both arms of the study. Seventy-seven percent of women preferred the CEE/PC to the CEE/MPA (P<.001). Of the 52 post-treatment endometrial biopsies: 40 revealed atrophic endometrium and 12 proliferative endometrium (7 in the oral progestin group and 5 in the PC group). There was no evidence of endometrial hyperplasia in any of the specimens. The incidence of vaginal spotting was similar in both groups.  Conclusion: Patients preferred transdermal PC over oral MPA. These preliminary data indicate that CEE/PC has a similar effect on the endometrium as standard oral HT over a 6-month period.
  
  
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