Micronized progesterone improves sleep outcomes in postmenopausal women

Micronized progesterone has been shown to improve sleep outcomes, especially among postmenopausal women, in randomized controlled trials (RCTs), according to the results of a systematic review and meta-analysis.

“Preclinical data has shown progesterone metabolites improve sleep parameters through positive allosteric modulation of the γ-aminobutyric acid type A receptor,” the investigators said.

The databases of Medline, Embase, PsycInfo, and the Cochrane Central Register of Controlled Trials were searched using preferred reporting items for systematic review and meta-analysis guidelines. The investigators identified RCTs of micronized progesterone treatment on sleep outcomes up to 31 March 2020 and used a random effects model for quantitative analysis.

Nine RCTs comprising 388 participants were included in the meta-analysis. One additional unpublished trial was also found. Of the studies, eight enrolled postmenopausal women. Compared with placebo, micronized progesterone resulted in improvements of various sleep parameters as measured by polysomnography, including total sleep time and sleep onset latency, albeit inconsistent studies.

In a meta-analysis of four RCTs, micronized progesterone improved sleep onset latency (effect size, 7.10, 95 percent confidence interval [CI], 1.30–12.91) but not total sleep time (effect size, 20.72, 95 percent CI, –0.16 to 41.59) or sleep efficiency (effect size, 1.31, 95 percent CI, –2.09 to 4.70).

Self-reported sleep outcomes improved in most trials. However, concomitant oestradiol administration and improvement in vasomotor symptoms limited the conclusions in some studies.

“Further research could evaluate the efficacy of micronized progesterone monotherapy using polysomnography or validated questionnaires in larger cohorts,” the investigators said.