Maca (L. meyenii) for erectile dysfunction: a systematic review and meta-analysis

Maca (Lepidium meyenii) has been reported to improve erectile function (EF). The purpose of this study was to evaluate the clinical evidence for or against maca as a therapy for erectile dysfunction (ED) in men. We searched 11 databases for randomized controlled trials (RCTs) comparing any type of maca with a placebo in the treatment of ED in men. The primary endpoint was EF, while the secondary endpoints were quality of life and adverse events. Risk of bias (ROB) was assessed using the Cochrane ROB tool 2.0. Study selection, data extraction, and assessment were independently performed by two researchers. RevMan 5.4.1 software (Cochrane Collaboration, 2020) was used for data aggregation, and the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) assessment was used to evaluate the quality of the study outcomes. Only two RCTs met all the inclusion criteria. These RCTs examined the effects of maca on EF in patients with mild ED. One RCT showed a positive effect of maca on EF, whereas the other RCT did not. The results of the meta-analysis indicate that maca has positive effects on EF in men with mild ED (n = 79, MDs 1.13: 0.64 to 1.61, p = 0.01; p < 0.0001). Our comprehensive review found limited evidence for the benefits of maca in improving EF. Several limitations, including the total number of studies and their sample sizes, were insufficient to draw firm conclusions. Further studies are needed.

Lepidium meyenii; Maca; Erectile dysfunction; Systematic review

[1] Johnston BC, Thorlund K, Schünemann HJ, Xie F, Murad MH, Montori VM, et al. Improving the interpretation of quality of life evidence in meta-analyses: the application of minimal important difference units. Health and Quality of Life Outcomes. 2010; 8: 116.

[2] EAU. EAU Guidelines. Edn. presented at the EAU Annual Congress Am-sterdam 2022. 2022. Available at: http://uroweb.org/guidelines/compilations-of-all-guidelines (Accessed: 07 August 2022).

[3] Yao H, Wang X, Liu H, Sun F, Tang G, Bao X, et al. Systematic review and meta-analysis of 16 randomized controlled trials of clinical outcomes of low-intensity extracorporeal shock wave therapy in treating erectile dysfunction. American Journal of Men’S Health. 2022; 16: 155798832210875.

[4] Garrido-Abad P, Senra-Bravo I, Manfredi C, Fernández-Pascual E, Linares-Espinós E, Fernández-Arjona M, et al. Combination therapy with topical alprostadil and phosphodiesterase-5 inhibitors after failure of oral therapy in patients with erectile dysfunction: a prospective, two-arm, open-label, non-randomized study. International Journal of Impotence Research. 2022; 34: 164–171.

[5] Manfredi C, Fortier É, Faix A, Martínez-Salamanca JI. Penile implant surgery satisfaction assessment. The Journal of Sexual Medicine. 2021; 18: 868–874.

[6] Otero JR, Manfredi C, Wilson SK. The good, the bad, and the ugly about surgical approaches for inflatable penile prosthesis implantation. International Journal of Impotence Research. 2022;34: 128–137.

[7] Schoentgen N, Califano G, Manfredi C, Romero-Otero J, Chun FKH, Ouzaid I, et al. Is it worth starting sexual rehabilitation before radical prostatectomy? Results from a systematic review of the literature. Frontiers in Surger. 2021; 8: 648345.

[8] Yafi FA, Jenkins L, Albersen M, Corona G, Isidori AM, Goldfarb S, et al. Erectile dysfunction. Nature Reviews. Disease Primers. 2016; 2: 16003.

[9] Ernst E, Posadzki P, Lee MS. Complementary and alternative medicine (CAM) for sexual dysfunction and erectile dysfunction in older men and women: an overview of systematic reviews. Maturitas. 2011; 70: 37–41.

[10] Lee HW, Lee MS, Kim TH, Alraek T, Zaslawski C, Kim JW, et al. Ginseng for erectile dysfunction. The Cochrane Database of Systematic Reviews. 2021; 4: CD012654.

[11] Tharakan B, Manyam BV. Botanical therapies in sexual dysfunction. Phytotherapy Research. 2005; 19: 457–463.

[12] Wang Y, Wang Y, McNeil B, Harvey LM. Maca: an Andean crop with multi-pharmacological functions. Food Research International. 2007; 40: 783–792.

[13] Lee MS, Lee HW, You S, Ha K. The use of maca (Lepidium meyenii) to improve semen quality: a systematic review. Maturitas. 2016; 92: 64–69.

[14] Gonzales GF, Ruiz A, Gonzales C, Villegas L, Cordova A. Effect of Lepidium meyenii (maca) roots on spermatogenesis of male rats. Asian Journal of Andrology. 2001; 3: 231–233.

[15] Zheng BL, He K, Kim CH, Rogers L, Shao Y, Huang ZY, et al. Effect of a lipidic extract from Lepidium meyenii on sexual behavior in mice and rats. Urology. 2000; 55: 598–602.

[16] Lee HW, Lee MS, Qu F, Lee JW, Kim E. Maca (Lepidium meyenii Walp.) on semen quality parameters: a systematic review and meta-analysis. Frontiers in Pharmacology. 2022;13: 934740.

[17] Shin B, Lee MS, Yang EJ, Lim H, Ernst E. Maca (L. meyenii) for improving sexual function: a systematic review. BMC Complementary and Alternative Medicine. 2010; 10: 44.

[18] Zhang Y, Zhou F, Ge F. Effects of combined extracts of Lepidium meyenii and Allium tuberosum Rottl. on erectile dysfunction. BMC Complementary and Alternative Medicine. 2019; 19: 135.

[19] Lee HW, Lee MS. Maca (Lepidium meyenii) for erectile dysfunction: a systematic review and meta-analysis. 2022. Available at: https://www.researchregistry.com/browse-the-registry#registryofsystematicreviewsmeta-analyses/registryofsystematicreviewsmeta-analysesdetails/ 626145fe4276e5001eccdd71/ (Accessed: 21 April 2022).

[20] Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ . 2021; 372: n71.

[21] Sterne JAC, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ. 2019; 366: l4898.

[22] Liu J. GRADE Methods in traditional medicine. Integrative Medicine Research. 2022;11: 100836.

[23] Ito M, Morii H, Kosaka T, Shizume M. Beneficial effects of maca (Lepidium meyenii) extract-containing diet on sexual dysfunction, particularly erectile dysfunction (ED), and related health conditions in middle-aged and older men with mild to moderate ED. Japanese Pharmacology and Therapeutics. 2019; 47: 1483–1495.

[24] Zenico T, Cicero AF, Valmorri L, Mercuriali M, Bercovich E. Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial. Andrologia. 2009; 41: 95–99.

[25] Deeks JJ, Higgins JP, Altman DG. Analysing data and undertaking meta‐analyses. Cochrane Handbook for Systematic Reviews of Interventions. 2019; 2: 241–284.