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Prostate Health

The research of Dr. GF Gonzales and his colleagues is robust on maca’s impact on prostate health, as demonstrated by multiple animal studies. Further, red maca appears to be the phenotype that has the most impact on prostate health, compared to other colors, such as black and yellow, which have shown to be beneficial for other areas of men’s reproductive health. Red maca has been shown to decrease prostate weight and act as an anti-inflammatory agent (1). At present, no human studies have been conducted to explore maca’s impact on prostate health. 


Benign prostatic hyperplasia (BPH) is characterized by increased prostate size and urinary tract symptoms. Finasteride, a 5-alpha reductase inhibitor, is a standard treatment and, therefore, has been employed in many studies as a control or comparison (1). In animal studies, BPH is commonly induced by subcutaneous injection of testosterone enanthate (TE) or testosterone propionate (TP).


Gonzales and other researchers have conducted multiple studies that have shown the effects of red maca’s ability to reduce prostate weight. This is influenced by the form of maca, the dose, and the length of treatment. One study found a reduction in prostate weight as early as day 1 of treatment (2). Another study showed that a hydroalcoholic extract of red maca reduced prostate weight in 21 days by 1.59 times (3), whereas hydroalcoholic and aqueous extracts containing 0.1 mg of benzylglucosinolates both reduced prostate weight (4). As indicated, dose also has been shown to be important. For example, a dose of 0.1 and 0.5 g/kg body weight of a freeze-dried aqueous extract of red maca resulted in higher reductions in prostate weights compared to 0.01, 0.05 g/kg body of the same maca extract and, notably, performed better than finasteride (5). When compared to yellow and black maca, only red maca was able to significantly reduce prostate size (p<0.05) (6,7).


A study in 2020 aimed to assess the effects red maca and finasteride would have on inflammatory pathways in BPH in rats. Tumor necrosis factor-alpha (TNF-a), interleukin 4 (IL-4) and interferon-gamma (INF-g) were measured. Red maca, in doses of 40 mg and 80 mg, and finasteride treatments decreased inflammatory cells counts in the prostate, but did so in different pathways. Finasteride increased IL-4, whereas red maca increased INF-g. The authors report that this finding suggests finasteride acts on the Th2 response while red maca acts on Th1 response (8). Of note, an increase in interferon-gamma was also observed in a study on ovariectomized rats when using red maca (9).


Methanolic red maca extract and its n-butanol (alkaloidal) and aqueous fractions were studied for their effects on the expression of androgen and estrogen receptors in rats with TE-induced BPH to help understand the mechanism that red maca impact BPH. Red maca as a methanolic extract and n-butanol fraction reduced prostate weight in a similar manner to Finasteride, while the aqueous fraction increased androgen and ERα receptors, which stimulates prostate growth and explains why this form was ineffective in reducing BPH indicators. All maca groups restored the expression of ERβ, an important finding to help reestablish ERα and ERβ ratio and confirm that red maca has estrogenic effects biologically. The authors propose that red maca’s content of β-sitosterol, a component that inhibits 5α-reductase isoforms, may be to be the reason for its benefits on BPH (1).  


Image 1: Red maca methanolic extract (MetOH) and its butanolic (ButOH) and aqueous (Aq) fractions have a positive estrogenic effect by balancing ERα and ERβ expression levels, but Aq also possesses an androgenic effect increasing androgen receptor (AR) levels.

Image Credit: Fano D, Vásquez-Velásquez C, Gonzales-Castañeda C, Guajardo-Correa E, Orihuela PA, Gonzales GF. N-Butanol and Aqueous Fractions of Red Maca Methanolic Extract Exerts Opposite Effects on Androgen and Oestrogens Receptors (Alpha and Beta) in Rats with Testosterone-Induced Benign Prostatic Hyperplasia. Evid Based Complement Alternat Med. 2017;2017:9124240. doi: 10.1155/2017/9124240. Epub 2017 Dec 11. PMID: 29375645; PMCID: PMC5742461.  

It appears red maca can positively impact prostate health by:

  • Inhibiting the effect on dihydrotestosterone (DHT) conversion (5)

  • Containing glucosinolates and anthocyanins, two compounds that have antiproliferative and proapoptotic properties in prostate cancer cells (7)

  • Containing other compounds such as alkaloids, steroids, tannins, and saponins that have positive effects on prostate health

  • Reducing inflammation (8)

  • Restoring ERα and ERβ ratio (1)


This evidence also demonstrates the importance of differentiating the colors of maca when using them clinically. Black and yellow maca have not shown the same positive effects on prostate health, whereas red maca did not impact various parameters of men’s reproductive health to as black and yellow maca have shown. 


Minich et al. reported that a significant amount of research was being conducted on red maca during 2005-2010, which may have deterred the exploration of other colors of maca for prostate health. Further, it was noted that unpublished research from Meissner et al. that indicates a combination of black and red maca phenotypes, with an extract of saw palmetto berries may be more effective for prostate health (10).

Author: Corey Schuler, PhD, FNP

Reviewer: Kim Ross, DCN

Last Updated: February 16, 2024



1. Fano D, Vásquez-Velásquez C, Gonzales-Castañeda C, Guajardo-Correa E, Orihuela PA, Gonzales GF. N-Butanol and Aqueous Fractions of Red Maca Methanolic Extract Exerts Opposite Effects on Androgen and Oestrogens Receptors (Alpha and Beta) in Rats with Testosterone-Induced Benign Prostatic Hyperplasia. Evidence-based Complementary and Alternative Medicine. 2017;2017.

2. Gonzales C, Leiva-Revilla J, Rubio J, Gasco M, Gonzales GF. Effect of red maca (Lepidium meyenii) on prostate zinc levels in rats with testosterone-induced prostatic hyperplasia. Andrologia. 2012;44(SUPPL.1).

3. Gonzales GF, Gasco M, Malheiros-Pereira A, Gonzales-Castañeda C. Antagonistic effect of Lepidium meyenii (red maca) on prostatic hyperplasia in adult mice. Andrologia. 2008;40(3).

4. Gonzales GF, Vasquez V, Rodriguez D, Maldonado C, Mormontoy J, Portella J, et al. Effect of two different extracts of red maca in male rats with testosterone-induced prostatic hyperplasia. Asian J Androl. 2007;9(2).

5. Gasco M, Villegas L, Yucra S, Rubio J, Gonzales GF. Dose-response effect of Red Maca (Lepidium meyenii) on benign prostatic hyperplasia induced by testosterone enanthate. Phytomedicine. 2007;

6. Gonzales C, Rubio J, Gasco M, Nieto J, Yucra S, Gonzales GF. Effect of short-term and long-term treatments with three ecotypes of Lepidium meyenii (MACA) on spermatogenesis in rats. J Ethnopharmacol. 2006;103(3).

7. Gonzales GF, Miranda S, Nieto J, Fernández G, Yucra S, Rubio J, et al. Red maca (Lepidium meyenii) reduced prostate size in rats. Reprod Biol Endocrinol. 2005 Jan 20;3:5.

8. Vásquez-Velásquez C, Gasco M, Fano-Sizgorich D, Gonzales GF. Inflammatory pathway employed by Red Maca to treat induced benign prostatic hyperplasia in rats. Andrologia. 2020;52(3).

9. Leiva-Revilla J, Guerra-Castañon F, Olcese-Mori P, Lozada I, Rubio J, Gonzales C, et al. [Effect of red maca (Lepidium meyenii) on INF-γ levels in ovariectomized rats]. Rev Peru Med Exp Salud Publica. 2014;31(4):683–8.

10. Minich DM, Ross K, Frame J, Fahoum M, Warner W, Meissner HO. Not All Maca Is Created Equal: A Review of Colors, Nutrition, Phytochemicals, and Clinical Uses. Nutrients. 2024 Feb 14;16(4):530.

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