Purpose: To further investigate the efficacy of progesterone in the treatment of the symptoms of premenstrual syndrome (PMS).
Materials and methods: From an initial cohort of 25 subjects diagnosed with moderate to severe PMS, 17 reproductive age females completed the 7-month, double-blind, placebo controlled trial using 200-mg vaginal progesterone suppositories. Multiple modalities for evaluating symptoms were employed, including the Spielberger self-evaluation rating, the Beck depression inventory, and the Hamilton anxiety scale. In addition, each subject was interviewed by a psychiatrist on a monthly basis; ovulation was determined monthly using a basal body temperature chart; serum hormonal assays included beta endorphin, progesterone, follicle stimulating hormone, luteinizing hormone, estradiol, and prolactin.
Results: Hormonal assays confirmed no differences between treatment and control groups. Overall scores on all test vehicles were likewise not significantly different between the two groups; however, in the subcategory of nervous symptoms, a significant improvement was found in symptoms relating to tension, mood swings, irritability, anxiety and lack of control.
Conclusions: Metabolites of progesterone (pregnanolone and allopregnanolone) may play a physiologic role as anxiolytic agents, perhaps modifying mood and anxiety; the current study confirms the utility of twice daily, 200-mg progesterone vaginal suppositories, in the alleviation of some PMS symptoms relating to anxiety and irritability. Further evaluation may be warranted to ascertain which patients in the known heterogeneous PMS population may be most likely to benefit from such treatment.