Common names: Maca, black maca, red maca
Botanical names: Lepidium meyenii, Lepidium
peruvianum
© Chris Kilham
Parts used and where grown
Maca is a cruciferous vegetable in the
mustard family, related to radishes and turnips. Used as food and medicine in the Andes
Mountains of Peru, it is not known to occur naturally anywhere else in the world. The four
major cultivars of maca are red, black, cream, and purple; none has been definitely proven to
be medicinally superior to any other.
Maca has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
Historical or traditional use (may
or may not be supported by scientific studies)
Maca root has been an important food for the native people in the Andes of Peru, including
the Incas, for at least 2,000 years.1 It is eaten baked, dried, mixed with milk, or in a variety of other forms and dishes. It is
also traditionally believed to enhance strength, endurance, libido, and
fertility.2
Active constituents
Maca contains substantial quantities of protein, fat,
fiber, and minerals including iron, which
also contribute to its nutritional value. It also contains glucosinolates,3 the
strong-smelling compounds that are responsible for the pungent smell and taste of mustard
family plants. Neither these nor any other constituents in maca have definitively been shown
to contribute to its actions.
Preliminary studies have shown that maca can increase libido in healthy men.4 It
does this without influencing levels of testosterone or any other sex hormones.5
Healthy men who take maca have also been shown to have increased semen volume, increased sperm
counts, and enhanced sperm motility.6
Numerous animal studies show that maca extracts can increase sex drive and improve
fertility.7 8 9 Other studies support that it can relieve the
negative effects of stress reactions.10 The red cultivar, though not the black or
cream, also reduced enlarged prostates in rats.11
How much is usually taken?
The amount used successfully in studies so far has been 500 to 1,000 mg three times per day
of dried root powder in capsules.12
Are there any side effects or interactions?
Glucosinolates can cause goiter (swollen thyroid gland with decreased activity) if taken in
excess combined with a low-iodine diet. Though this is documented to occur with other
glucosinolate-rich foods, it is not known if maca causes goiter.
At the time of writing, there were no well-known drug interactions
with maca.
References:1. Valentova K, Ulrichova J. Smallanthus sonchifolius and Lepidium
meyenii - prospective Andean crops for the prevention of chronic diseases. Biomed Pap Med
Fac Univ Palacky Olomouc Czech Repub 2003;147:119–30.
2. Smith E. Maca root: Modern rediscovery of an ancient Andean fertility
food. J Amer Herbalists Guild 2003;4:15–21.
3. 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;50:5621–5.
4. Gonzales GF, Cordova A, Vega K, et al. Effect of Lepidium meyenii
(maca) on sexual desire and its absent relationship with serum testosterone levels in adult
healthy men. Andrologia 2002;34:367–72.
5. Gonzales GF, Cordova A, Vega K, et al. 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;176:163–8.
6. Gonzales GF, Cordova A, Gonzales C, et al. Lepidium meyenii (maca)
improved semen parameters in adult men. Asian J Androl 2001;3:301–3.
7. Cicero AF, Piacente S, Plaza A, et al. Hexanic maca extract improves
rat sexual performance more effectively than methanolic and chloroformic maca extracts.
Andrologia 2002;34:177–9.
8. Gonzales GF, Ruiz A, Gonzales C, et al. Effect of Lepidium meyenii
(maca) roots on spermatogenesis of male rats. Asian J Androl 2001;3:231–3.
9. Ruiz-Luna AC, Salazar S, Aspajo NJ, et al. Lepidium meyenii (maca)
increases litter size in normal adult female mice. Reprod Biol Endocrinol
2005;3:16.
10. Lopez-Fando A, Gomez-Serranillos MP, Iglesias I, et al. Lepidium
peruvianum Chacon restores homeostasis impaired by restraint stress. Phytother Res
2004;18:471–4.
11. Gonzales GF, Miranda S, Nieto J, et al. Red maca (Lepidium meyenii)
reduced prostate size in rats. Reprod Biol Endocrinol 2005;3:5.
12. Gonzales GF, Cordova A, Gonzales C, et al. Lepidium meyenii (maca)
improved semen parameters in adult men. Asian J Androl 2001;3:301–3.