top of page

Safety of Maca

Maca became popular in the 1990s as a supplement, however, maca has been used for thousands of years by Peruvians as a food source and for its medicinal properties (1). Andean people consume maca in various ways (1–3):

  • Macachincha: A fermented, sweet drink

  • Pachamanca: Roots baked in an underground pit

  • Mazamorra: Boiled and eaten as a porridge

  • Made into jams, pudding, alcoholic cocktails and empanadas

  • Consumed as a juice


It has been noted that Peruvians consume up to 100 grams of maca per day, on average (1).

Therefore, it is not surprising to see that studies have shown maca to be very safe, overall (3). Using an LD50 toxicity test, more than 15g/kg body weight in mice and more than 7.5 g/kg body weight in rats found no adverse or toxicity concerns (4,5). This dose is much higher than a human would consume. Further, no liver or neurological toxicity occurred in animal models at 1 g/kg/body weight and 10g/kg body weight, respectively (3).

Limited adverse effects have been noted in human clinical trials. This includes:

  • Minor gastrointestinal symptoms (N=2), using a gelatinized black maca from an undisclosed location. This did not inhibit the participants from continuing with the trial (6)

  • Possible starch intolerance (N=1), using a gelatinized yellow maca from Peru (7)

  • These events were reported as transient and did not lead to discontinuation of the supplement. The form, color, location grown, and agricultural methods of the maca used in this study were not reported (8).GI upset (N= 5), headache (N=2), irritability (N= 2), panic attack (N=1), urinary frequency (N=1), blurry vision (N=1), sleep disruption (N=1), increased sweating (N=1), increased dreaming (N=1), thicker menstrual discharge (N=1), and fibromyalgia exacerbation (N=1).


One case report described a manic episode that occurred after taking a supplement for 2 weeks that contained maca, though the details are unclear as to the dose and other ingredients in the supplement (9). Fresh pulverized maca taken for 60 days in a dose of 115 grams per day, resulted in no adverse liver or renal toxicity (3).

One study reported that 4% of participants did not like the taste, however, this was not a safety concern (10).

In 2009, the United States Pharmacopeia conducted an evaluation to investigate safety concerns. It was concluded that maca root, maca root powder, and maca root dry extract, posed no safety concerns, as there were no serious adverse events. This data was reevaluated in 2017 and it remained that maca did not pose safety concerns (3).
With this in mind, safety concerns have recently arisen in the literature. Dokkedal-Silva, et al. expressed concerns about the safety of the plant, in part due to the concerns about it being a stimulant and the effect it, therefore, may have on sleep (11). However, this is debatable since maca is accepted to be an adaptogen within botanical medicine (12), in which simulant-like activities would occur only if this was needed to restore homeostasis.

The same group pointed out concerns from a study published in 2007 about one of maca’s chemical compounds, MTCA (methyltetrahydro-B-carbolines) (11). While the effects of MTCA may pose health risks (inhibiting monoamine oxidase enzyme and playing a role in addiction), the findings of MTCA in maca have been disputed since the compound is deactivated during the preparation (boiling) process (13,14) and the polyphenols in maca inhibit the detrimental effects, concluding this compound is non-toxic (14).

In summary, maca is considered safe, with toxicity levels tested well above what is normally consumed by humans as a food or supplement source. Minor adverse effects may be experienced by a small number of people, though they seem transient and do not appear to contribute to the cessation of use.

Author: Kim Ross, DCN

Reviewer: Mona Fahoum, ND

Last Updated; July 22, 2024

​

References

​

1. Beharry S, Heinrich M. Is the hype around the reproductive health claims of maca (Lepidium meyenii Walp.) justified? Journal of Ethnopharmacology. 2018.
2. Gonzales GF, Gasco M, Lozada-Requena I. Role of Maca (Lepidium meyenii) Consumption on Serum Interleukin-6 Levels and Health Status in Populations Living in the Peruvian Central Andes over 4000 m of Altitude. Plant Foods for Human Nutrition. 2013;68(4).
3. Ulloa del Carpio N, Alvarado-Corella D, Quiñones-Laveriano DM, Araya-Sibaja A, Vega-Baudrit J, Monagas-Juan M, et al. Exploring the chemical and pharmacological variability of Lepidium meyenii: a comprehensive review of the effects of maca. Front Pharmacol. 2024 Feb 19;15.
4. Meissner HO, Mrozikiewicz P, Bobkiewicz-Kozlowska T, Mscisz A, Kedzia B, Lowicka A, et al. Hormone-Balancing Effect of Pre-Gelatinized Organic Maca (Lepidium peruvianum Chacon): (I) Biochemical and Pharmacodynamic Study on Maca using Clinical Laboratory Model on Ovariectomized Rats. Int J Biomed Sci. 2006;
5. Meissner HO, Kedzia B, Mrozikiewicz PM, Mscisz A. Short and long-term physiological responses of male and female rats to two dietary levels of pre-gelatinized maca (lepidium peruvianum chacon). Int J Biomed Sci. 2006;
6. Shin D, Jeon SH, Piao J, Park HJ, Tian WJ, Moon DG, et al. Efficacy and Safety of Maca (Lepidium meyenii) in Patients with Symptoms of Late-Onset Hypogonadism: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. World Journal of Men’s Health. 2023;41(3).
7. Melnikovova I, Russo D, Fait T, Kolarova M, Tauchen J, Kushniruk N, et al. Evaluation of the effect of Lepidium meyenii Walpers in infertile patients: A randomized, double-blind, placebo-controlled trial. Phytotherapy Research. 2021;35(11).
8. Dording CM, Schettler PJ, Dalton ED, Parkin SR, Walker RSW, Fehling KB, et al. A double-blind placebo-controlled trial of maca root as treatment for antidepressant-induced sexual dysfunction in women. Evidence-based Complementary and Alternative Medicine. 2015;2015.
9. Quandt P, Puga M. Manic episode secondary to maca. European Psychiatry. 2016;33(S1).
10. Gonzales-Arimborgo C, Yupanqui I, Montero E, Alarcón-Yaquetto DE, Zevallos-Concha A, Caballero L, et al. Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii) in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study. Pharmaceuticals (Basel). 2016 Aug 18;9(3).
11. Dokkedal-Silva V, Morelhão PK, Tufik S, Andersen ML. The increasing popularity of Peruvian maca (Lepidium meyenii) and its potential impacts on sleep and quality of life. Clinics (Sao Paulo). 2024;79:100398.
12. 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.
13. Corazza O, Martinotti G, Santacroce R, Chillemi E, Di Giannantonio M, Schifano F, et al. Sexual enhancement products for sale online: Raising awareness of the psychoactive effects of yohimbine, maca, horny goat weed, and ginkgo biloba. Vol. 2014, BioMed Research International. 2014.
14. Gonzales GF, Gonzales-Castañeda C. The methyltetrahydro-β-carbolines in Maca (Lepidium meyenii). Vol. 6, Evidence-based Complementary and Alternative Medicine. 2009.

bottom of page