Maca (Lepidium meyenii)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
Acyclic keto acid, alkaloids, amino, Andean Viagra®, anthocyanines, aromatic glucosinolates, ayak chichira (Quechua/Spanish), ayuk willku (Quechua/Spanish), benzaldehyde, benzyl glucosinolate (glucotropaeolin), beta-ecdysone, Brassicaceae (family), calcium, carboline, cardiotonic glycosides, campesterol, chicha de maca (Spanish), Cruciferae (former family name), fatty acids, flavonoids, glucosinolate degradation products, glucotropaeolin, imidazole alkaloids, iron, isopteropodin, Lepidieae (tribe), lepidiline A, lepidiline B, Lepidium apetalum, Lepidium meyenii, Lepidium peruvianum Chacón, Lepidium sativum L., maca chicha, maca maca, macaenes, macamides, macaridine, mace, magnesium, maino, maka, malic acid, matia, methoxybenzyl isothiocyanate, natural Viagra®, pepperweed, Peruvian ginseng, Peruvian maca, phenyl acetonitrile, phosphorus, potassium, prostaglandins, protein, quercitin, saponins, sitosterols, steroids, stigmasterol, tannins, uridine, vitamin B1, vitamin B12, vitamin C, vitamin E, vitamin K, zinc.
Maca is a vegetable that has been cultivated as a root crop for at least 2,000 years. It can be found wild in Peru, Bolivia, Paraguay, and Argentina, but has primarily been cultivated in the highlands of the Peruvian Andes. Because of its ability to grow in harsh climates at high-altitude, maca is an important staple food for native populations in the Peruvian highlands. It is highly nutritious with about 11% protein content and can be baked, roasted, prepared as a porridge, and has been used for making a fermented drink.
Traditionally, maca has also been used to relieve stress, as an aphrodisiac, and for fertility enhancement in both males and females. Recently, commercial maca products have gained popularity in areas outside of South America as dietary supplements, with claims of boosting energy, enhancing fertility, balancing hormones, acting as an aphrodisiac, and enhancing sexual performance. However, evidence to support these claims is weak.
Natives of the central Andes do not use fresh maca. It is considered harmful. When maca is harvested, the roots are dried by exposing them to sunlight for 4-6 days. After they have been dried, they can be stored in cool, dark places for several years. For consumption, the dried roots are rehydrated by boiling them in water until they are soft. Maca is also referred to as Peruvian ginseng, although it is not closely related to ginseng.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Traditionally in Peru, maca has been used as an aphrodisiac. Maca could improve sexual desire in healthy men independent of changes in mood, or serum testosterone, and estradiol levels. Higher quality studies are needed in this area, in both men and women.
Hormone regulation (male)
Traditionally, maca has been used in Peru to enhance fertility. One study did not demonstrate that maca ingestion could change levels of luteinizing hormone, follicle-stimulating hormone, prolactin, hydroxyprogesterone, testosterone, or estradiol. Additional study is needed before a firm conclusion can be made.
Maca has been traditionally used in Peru to enhance fertility of both people and animals. Maca may improve semen quality, however, additional study is needed to confirm this finding.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
Adaptogen, AIDS, anabolic, anemia, anxiety, aphrodisiac (female), athletic performance, cancer, chronic fatigue syndrome, cognitive function, depression, fertility, food uses, hepatoprotection, hormonal imbalances (female), immunostimulant, joint diseases, leukemia, menstrual irregularities, metabolic enhancement, nutritional supplement, osteoporosis (postmenopausal), prostate enlargement, sexual function, sexual performance, stimulant, tonic, tuberculosis.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
Maca is likely safe when consumed by healthy adults in doses of 1,500-3,000 milligrams per day for up to four months as an aphrodisiac or to improve spermatogenisis, however, there is no proven effective dose for maca. Traditionally, up to 6,000 milligrams or more per day in divided doses has been used. Root powder containing 2,800 milligrams of maca root placed in 8 ounces of water has also been used up to three times daily. Commercially prepared concentrated extracts containing 450 milligrams taken twice daily has been used as well.
Common dietary consumption in native populations is greater than 100 grams, or equivalent to greater than 1.4g per kilogram, daily.
Children (younger than 18 years)
There is no proven safe or effective dose of maca, and use in children is not recommended.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid in individuals with a known allergy or hypersensitivity to maca (Lepidium meyenii).
Side Effects and Warnings
Available studies in humans have only been performed on male subjects. In these trials, no side effects were noted and maca was generally considered safe. Maca has not been studied in women.
Maca may cause changes in some sex hormones, although animal studies have demonstrated conflicting results. Preliminary evidence from studies in humans has failed to show that maca induces changes in luteinizing hormone, follicle stimulating hormone, prolactin, testosterone, and estradiol. However, use cautiously in patients with hormone responsive cancers such as breast cancer, or prostate cancer, and patients who are using birth control pills due to the potential effects of maca on sex hormone regulation.
Consumption of large amounts of maca may cause bloating and flatulence. Consumption of fresh maca may cause stomach pain.
The use of maca may increase leukocytes. The use of maca may decrease PT/INR values in patients being monitored for anticoagulation therapy.
Maca may also lead to stimulation of the central nervous system. Use cautiously in patients with hypertension (high blood pressure), due to the possibility of central nervous system stimulation.
Pregnancy and Breastfeeding
Maca is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Plants in the Brassicaceae family, such as maca, are often rich in vitamin K. Thus, maca may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Maca may act as a stimulant and cause hypertension (high blood pressure). Patients taking medication for high blood pressure, or those taking other stimulant medications, should consult with a qualified healthcare professional, including a pharmacist, before combining therapies.
Maca may alter the levels of sex hormones, and may interfere with the effects of hormone replacement therapy or birth control pills. Caution is advised.
Interactions with Herbs and Dietary Supplements
Plants in the Brassicaceae family, such as maca, are often rich in vitamin K. Maca may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases
Maca may act as a stimulant and cause hypertension (high blood pressure). Patients taking herbs or supplements for high blood pressure, or those taking other stimulants, should consult with a qualified healthcare professional, including a pharmacist, before combining therapies.
Maca may alter the levels of sex hormones, and may interfere with the effects of herbs or supplements with hormone effects, such as St. John's wort or chasteberry.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Bogani P, Simonini F, Iriti M, et al. Lepidium meyenii (Maca) does not exert direct androgenic activities. J Ethnopharmacol 4-6-2006;104(3):415-417. View Abstract
Bustos-Obregon E, Yucra S, Gonzales GF. Lepidium meyenii (Maca) reduces spermatogenic damage induced by a single dose of malathion in mice. Asian J Androl 2005;7(1):71-76. View Abstract
Chung F, Rubio J, Gonzales C, et al. Dose-response effects of Lepidium meyenii (Maca) aqueous extract on testicular function and weight of different organs in adult rats. J Ethnopharmacol. 4-8-2005;98(1-2):143-147. View Abstract
Gonzales C, Rubio J, Gasco M, et al. Effect of short-term and long-term treatments with three ecotypes of Lepidium meyenii (MACA) on spermatogenesis in rats. J Ethnopharmacol 2-20-2006;103(3):448-454. View Abstract
Gonzales GF, Miranda S, Nieto J, et al. Red maca (Lepidium meyenii) reduced prostate size in rats. Reprod.Biol Endocrinol 1-20-2005;3(1):5. View Abstract
McCollom MM, Villinski JR, McPhail KL, et al. Analysis of macamides in samples of Maca (Lepidium meyenii) by HPLC-UV-MS/MS. Phytochem.Anal. 2005;16(6):463-469. View Abstract
McKay D. Nutrients and botanicals for erectile dysfunction: examining the evidence. Altern Med Rev 2004;9(1):4-16. View Abstract
Miller MJ, Ahmed S, Bobrowski P, et al. The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1beta. BMC.Complement Altern Med 2006;6:13. View Abstract
Rubio J, Caldas M, Davila S, et al. Effect of three different cultivars of Lepidium meyenii (Maca) on learning and depression in ovariectomized mice. BMC.Complement Altern Med 6-23-2006;6(1):23. View Abstract
Rubio J, Riqueros, MI, Gasco M, et al. Lepidium meyenii (Maca) reversed the lead acetate induced-Damage on reproductive function in male rats. Food Chem Toxicol 2006;44(7):1114-1122. View Abstract
Ruiz-Luna AC, Salazar S, Aspajo NJ, et al. Lepidium meyenii (Maca) increases litter size in normal adult female mice. Reprod.Biol Endocrinol 5-3-2005;3(1):16. View Abstract
Valentova K, Buckiova D, Kren V, et al. The in vitro biological activity of Lepidium meyenii extracts. Cell Biol Toxicol 2006;22(2):91-99. View Abstract
Valerio LG Jr, Gonzales GF. Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii) : a critical synopsis. Toxicol.Rev 2005;24(1):11-35. View Abstract
Zhang Y, Yu L, Ao M, et al. Effect of ethanol extract of Lepidium meyenii Walp. on osteoporosis in ovariectomized rat. J Ethnopharmacol 4-21-2006;105(1-2):274-279. View Abstract
Zhao J, Muhammad I, Dunbar DC, et al. New alkamides from maca (Lepidium meyenii). J Agric.Food Chem. 2-9-2005;53(3):690-693. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017