OBJECTIVE: To evaluate the efficacy of progesterone and progestogens in the management of premenstrual syndrome. DESIGN: Systematic review of published randomised, placebo controlled trials. Studies reviewed: 10 trials of progesterone therapy (531 women) and four trials of progestogen therapy (378 women). MAIN OUTCOME MEASURES: Proportion of women whose symptoms showed improvement with progesterone preparations (suppositories and oral micronised). Proportion of women whose symptoms showed improvement with progestogens. Secondary analysis of efficacy of progesterone and progestogens in managing physical and behavioural symptoms. RESULTS: Overall standardised mean difference for all trials that assessed efficacy of progesterone (by both routes of administration) was -0.028 (95% confidence interval -0.017 to -0.040). The odds ratio was 1.05 (1.03 to 1.08) in favour of progesterone, indicating no clinically important difference between progesterone and placebo. For progestogens the overall standardised mean was -0.036 (-0.014 to -0.060), which corresponds to an odds ratio of 1.07 (1.03 to 1.11) showing a statistically, but not clinically, significant improvement for women taking progestogens. CONCLUSION: The evidence from these meta-analyses does not support the use of progesterone or progestogens in the management of premenstrual syndrome.