Possible Interaction: Estradiol and Progesterone

“Serum levels of estradiol and progesterone were significantly higher in the LUT versus the FOL phase of the menstrual cycle.”

“However, the addition of cyclic oral micronized progesterone to intranasal estradiol influenced the markers of cardiovascular risk negatively in comparison to non-users in healthy postmenopausal women.”

“Correspondingly, estradiol and progesterone levels decreased during treatment.”

“Hormone analysis also showed an interaction between S-estradiol and S-progesterone on pain intensity, demonstrating that the increased perceived pain intensity that was associated with high progesterone concentrations was significantly reduced with increasing levels of estradiol.”

“Conclusion: Adding estradiol to progesterone for luteal phase support in ICSI-ET cycles may increase implantation and pregnancy rates.”

“The addition of oestradiol to the luteal supplement suppresses endogenous corpus luteum progesterone secretion irrespective of the type of assisted conception cycle and that its use is unlikely to be beneficial to the process of implantation.”

“There was a modest decrease in total and LDL cholesterol during treatment both with estradiol alone and when estradiol was combined with progesterone (all P<0.001 versus placebo).”

“ Progesterone concentration was positively correlated with both oestradiol concentration (r = 0.290; P < 0.05) and the number of oocytes retrieved (r = 0.207; P < 0.05).”

“Moreover, in these cycles serum luteal oestradiol concentrations were decreased significantly (350 +/- 77 versus 657 +/- 104 pg/ ml) compared with the classic step-up protocol.”

“These data indicate that the proliferative stimulus of the mammary lobule is more intense during the luteal phase of the normal cycle and may probably be due to a synergistic action between progesterone and estradiol.”