Vaginal progesterone gel may be preferable for luteal phase support

Vaginally applied progesterone gel provides higher endometrial levels and lower systemic levels of progesterone than intramuscularly administered progesterone, according to a prospective, randomized study involving 32 postmenopausal women. All of the participants used transdermal estradiol (50 ?g/day, a patch each week) for 2 weeks. In addition, they used 50 mg of either vaginal progesterone gel or IM progesterone in oil after 24 hours to oppose the transdermal estradiol.