Menopause is associated with bothersome symptoms for many women, including mood changes, hot flushes, sleep problems, and fatigue. Progesterone is commonly prescribed in combination with estrogen therapy. Although monotherapy with progestins has been used as treatment of menopausal symptoms in women with contraindications to estrogens, the optimal route, and dosage of progestin monotherapy has not been established.
To assess whether progestin as a standalone treatment is effective for treating vasomotor and mood symptoms associated with menopause.
We conducted a systematic review using PubMed and Embase databases from January 1980 to January 2020. We included randomized controlled trials (RCTs) that investigated different forms of progestin for the treatment of vasomotor or mood symptoms associated with menopause.
A systematic search of 892 studies identified seven RCTs involving a total of 601 patients. The available literature was heterogeneous in terms of formulation and dose of progesterone; administration ranged from 5 to 60 mg of transdermal progesterone, 10 to 20 mg oral medroxyprogesterone acetate, and 300 mg of oral micronized progesterone. Duration of treatment also differed between studies, ranging from 21 days to 12 months (median: 12 wks). Three of seven RCTs reported that progestin therapy led to an improvement of vasomotor symptoms (VMS) in postmenopausal women. The largest study administering oral progestin using 300 mg micronized progesterone reported a 58.9% improvement in VMS (vs 23.5% in placebo group, n = 133), whereas the largest study using transdermal progesterone reported no improvement (n = 230). No study reported an improvement of mood symptoms. Side effects, such as headaches and vaginal bleeding, were significant in five of seven RCTs and led to discontinuation of treatment in 6% to 21% of patients.
Conclusions and relevance:
A beneficial effect was reported in some trials with the transdermal route at longer duration and with oral treatment at higher doses for VMS for progesterone-only therapy. This report may help to inform future studies of progestin-only therapy for the treatment of menopausal symptoms.