Maca is a South American tuber that has been used since ancient times as a staple food crop in the Andes. Although maca has been long known as a folkloric medicine and food for increasing energy, physical and mental endurance and stamina, it has recently been in the spotlight for its use in altering sexual function (Balick and Lee, 2002). Maca is thought to be able to increase libido in both men and women, although this effect has only clinically been tested in men. Recent preliminary clinical studies have shown that maca has effects on increasing libido and fertility that are independent of sexual hormone functioning and parameters of mood (depression and anxiety). Several positive studies have been performed in animals (mice) and found increased sexual performance, libido and fertility parameters (Cicero et al., 2002; Cicero et al., 2001; Gonzales et al., 2001; Zheng et al., 2000).
It is interesting to note that the tall physical height and strength of the people of the Andes who live at such high elevations (where maca was popular as a food staple) has been theorized to be linked to the use of maca in their diet (Canales et al., 2000). Maca is rich in nutrients, such as amino acids and glucosinolates, which have been linked to its activity (Piacente et al., 2002).
The jury is still out as to the best dosage form and health conditions for which maca benefits, however, the clinical evidence of its effect in altering libido and fertility is promising. In either case, maca enjoys a long history of use as a food that makes people feel good and strong and it continues to do so in Peru and in the Andes of South America.
Hormonal Regulation, Mood and Libido
In a randomized, double-blind, placebo-controlled, parallel study, maca was tested for its effect on hormone levels when administered for libido and fertility-enhancement. Maca was given in either 1500 mg or 3000 mg daily doses for 12 weeks and hormone levels were tested (serum lutenizing (LH), follicle stimulating hormone (FSH), prolactin (PRL), testosterone (T) and estradiol (E2), and 17-alpha hydroxyprogesterone). Maca was found not have any effect on reproductive hormone levels (Gonzales et al., 2003).
The reported effect of maca on libido was examined to see if it was related to serum testosterone or mood levels in a randomized, double-blind, placebo-controlled study. Either 1500 or 3000 mg of maca was given for 12 weeks and the self perception of sexual desire, Hamilton test for depression, and Hamilton test for anxiety was measured at 4, 8 and 12 weeks of treatment. At 8 weeks of treatment, maca produced an improvement in sexual desire, however, serum testosterone and oestradiol levels were not found to be changed. There was also no correlation found in Hamilton scores for depression or anxiety. The effect of maca on libido was found to be separate from testosterone or mood regulation (Gonzales et al., 2002).
The effect of Maca supplementation on semen function and health parameters was studied in a preliminary clinical study. Nine men were administered Maca (L. meyenii; 1500 or 3000 mg daily) for four months and seminal analysis was performed along with hormonal analysis on LH, FSH, PRL, T and E2. Seminal analysis followed guidelines of the World Health Organization (WHO). Maca was found to improve sperm production in a non-dose dependent manner by mechanisms not related to hormonal production (Gonzales et al., 2001).
Safety / Dosage
As it has a long historical use as a staple food, maca is thought to be very safe and free of side effects or drug interactions. Maca is generally recommended in dosages of 1.5-5 grams per day (of dried tuber), or approximately 900 mg of the extract daily. Different manufacturers have varying preparations, so it is best to read the label recommendations.
1.Balick MJ, Lee R. Maca: from traditional food crop to energy and libido stimulant. Altern Ther Health Med. 2002 Mar-Apr;8(2):96-8.
2.Canales M, Aguilar J, Prada A, Marcelo A, Huaman C, Carbajal L. Nutritional evaluation of Lepidium meyenii (MACA) in albino mice and their descendants. Arch Latinoam Nutr. 2000 Jun;50(2):126-33.
3.Cicero AF, Bandieri E, Arletti R. Lepidium meyenii Walp. improves sexual behaviour in male rats independently from its action on spontaneous locomotor activity. J Ethnopharmacol. 2001 May;75(2-3):225-9.
4.Cicero AF, Piacente S, Plaza A, Sala E, Arletti R, Pizza C. Hexanic Maca extract improves rat sexual performance more effectively than methanolic and chloroformic Maca extracts. Andrologia. 2002 Jun;34(3):177-9.
5.Gonzales GF, Cordova A, Vega K, Chung A, Villena A, Gonez C. Effect of Lepidium meyenii (Maca), a root with aphrodisiac and fertility-enhancing properties, on serum reproductive hormone levels in adult healthy men. J Endocrinol. 2003 Jan;176(1):163-8.
6.Gonzales GF, Cordova A, Vega K, Chung A, Villena A, Gonez C, Castillo S. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. Andrologia. 2002 Dec;34(6):367-72.
7.Gonzales GF, Cordova A, Gonzales C, Chung A, Vega K, Villena A. Lepidium meyenii (Maca) improved semen parameters in adult men. Asian J Androl. 2001 Dec;3(4):301-3.
8.Gonzales GF, Ruiz A, Gonzales C, Villegas L, Cordova A. Effect of Lepidium meyenii (maca) roots on spermatogenesis of male rats. Asian J Androl. 2001 Sep;3(3):231-3.
9.Piacente S, Carbone V, Plaza A, Zampelli A, Pizza C. Investigation of the tuber constituents of maca (Lepidium meyenii Walp.). J Agric Food Chem. 2002 Sep 25;50(20):5621-5.
10.Zheng BL, He K, Kim CH, Rogers L, Shao Y, Huang ZY, Lu Y, Yan SJ, Qien LC, Zheng QY. Effect of a lipidic extract from lepidium meyenii on sexual behavior in mice and rats. Urology. 2000 Apr;55(4):598-602.
EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS.