Herbal Dietary Supplements for Erectile Dysfunction: A Systematic Review and Meta-Analysis

Francesca Borrelli, Cristiano Colalto, Domenico V. Delfino, Marcello Iriti, Angelo A. Izzo

Erectile dysfunction (ED) is a common condition that significantly affects quality of life and interpersonal relationships. Our objective was to perform a systematic review and meta-analysis to evaluate the efficacy of herbal dietary supplements in the treatment of ED. We searched five databases to identify randomized controlled trials (RCTs) that evaluated the clinical efficacy of herbal medicines in ED. Quality was assessed and risk of bias was estimated using the Jadad score and the Cochrane risk-of-bias tool. In total, 24 RCTs, including 2080 patients with ED, were identified. Among these, 12 evaluated monopreparations (five ginseng [n = 399], three saffron [n = 397], two Tribulus terrestris [n = 202], and one each Pinus pinaster [n = 21] and Lepidium meyenii [n = 50]), seven evaluated formulations (n = 544), and five investigated dietary supplements in combination with pure compounds (n = 410). Ginseng significantly improved erectile function (International Index of Erectile Function [IIEF]-5 score: 140 ginseng, 96 placebo; standardized mean difference [SMD] 0.43; 95% confidence interval [CI] 0.15-0.70; P < 0.01; I2 = 0), P. pinaster and L. meyenii showed very preliminary positive results, and saffron and T. terrestris treatment produced mixed results. Several herbal formulations were associated with a decrease of IIEF-5 or IIEF-15, although the results were preliminary. The quality of the included studies varied, with only seven having a prevalent low risk of bias. The median methodological quality Jadad score was three out of a maximum of five. Adverse events were recorded in 19 of 24 trials, with no significant differences between placebo and verum in placebo-controlled studies. Encouraging evidence suggests that ginseng may be an effective herbal treatment for ED. However, further, larger, and high-quality studies are required before firm conclusions can be drawn. Promising (although very preliminary) results have also been generated for some herbal formulations. Overall, more research in the field, adhering to the CONSORT statement extension for reporting trials, is justified before the use of herbal products in ED can be recommended.