This clinical trial evaluated the effects of treating postmenopausal women with
hypoactive sexual desire disorder (HSDD) using Tribulus terrestris. All women received testing including mammography, vaginal ultrasounds, and serum levels of prolactin, thyroid stimulating hormone, total testosterone and sex hormone binding globulin before enrollment. Study participants were randomized to two groups with the treatment group receiving three pills of 250 mg of Tribulus terrestris for 120 days and the control group receiving placebo for 120 days.
The Female Sexual Function Index (FSFI) and the Sexual Quotient Female Version (QS-F) questionnaires were used to assess female sexual function. A total of 36 healthy postmenopausal women with low libido were selected to participate in this study in Brazil. All women were between 1 and 10 years postmenopausal and were between 43 and 65 years old. Women were excluded if they had interpersonal relationship problems or had partners with sexual problems.
A total of 36 women, with 20 in the study group and 16 in the placebo group, with three drop outs in each group. The total mean score and scores of each of the six FSFI questionnaire domains before and after treatment did not show any significant difference between the two groups. Women receiving the T terrestris scored significant improvements in all six domains as did the placebo did, with the exception of lubrication which did not improve in the placebo group.
After 120 days of treatment with T terrestris, the QS-F indicated significant improvement in the domains of desire, arousal/lubrication, pain and anorgasmia with the placebo group showing no improvements in any of these domains.
The initial testosterone levels in both groups did not vary before and after the treatment, although there was a significant increase in the levels of free and bioavailable testosterone in the T terrestris group with no increase in the placebo group.
Commentary: To my knowledge, this is the first study suggesting a treatment effect of T terrestris for HSDD in postmenopausal women. While there was improvement yet no difference between treatment group and placebo for the FSFI domains except lubrication, which did improve more in the treatment group, that is in fact important in comfort during vaginal penetration. And, if sex is anticipated to be comfortable and pain free, then the desire to have sex tends to improve. The other scale, the QS-F questionnaire is a tool designed to assess sexual function in Brazilian women specifically. It could be interpreted that this questionnaire is more representative of results in Brazilian women, which might explain the difference in results between the questionnaires.
Reference: Dias de Souza K, Vale, F, Geber S. Efficacy of Tribulus terrestris for the treatment of hypoactive sexual desired disorder in postmenopausal women: a randomized, double-blinded, placebo-controlled trial. Menopause 2017; 23;(11): 1252-1256
