Clomiphene citrate (Clomifene citrate) is a selective estrogen receptor modulator.Target: Estrogen Receptor/ERRClomifene citrate (CC) acted as an estrogen antagonist regardless of the concentration of E2 added together. In conclusion, CC acts as an estrogen agonist/antagonist via ER alpha in a coexisting estrogen concentration-dependent way whereas it acts as an estrogen antagonist via ER beta whether or not estrogen is present [1]. Clomiphene was effective in increasing pregnancy rate compared to placebo (OR 5.8, 95% CI 1.6 to 21.5) as was clomiphene plus dexamethasone treatment (OR 9.46, 95% CI 5.1 to 17.7) compared to clomiphene alone. A significant improvement in the pregnancy rate was reported for clomiphene plus combined oral contraceptives versus clomiphene alone. No evidence of a difference in effect on pregnancy rate was found with any of the other comparisons [2].
References:
[1]. Kurosawa, T., et al., Clomiphene citrate elicits estrogen agonistic/antagonistic effects differentially via estrogen receptors alpha and beta. Endocr J, 2010. 57(6): p. 517-21.
[2]. Brown, J., et al., Clomiphene and anti-oestrogens for ovulation induction in PCOS. Cochrane Database Syst Rev, 2009(4): p. CD002249.