maca root

Maca (Lepidium meyenii) is a root vegetable in the cabbage and mustard family. It is traditionally grown high in the Peruvian Andes, where it has long been eaten as a food. Sold as a dietary supplement, it usually comes as capsules, tablets, or powders made from the dried root.

Robust human evidence for maca is limited. Only a small number of clinical trials have been done in people, and their results are mixed; reviews have generally judged the evidence for sexual function and menopausal symptoms to be weak and inconclusive, and at least one review concluded maca does not work as an anti-aging agent. Some animal research looks more encouraging than the human data, but animal findings do not reliably predict effects in people. Overall, most claims about maca rest on tradition and preliminary research rather than strong proof. None of these claims are supported by an NIH Office of Dietary Supplements, NCCIH, or MedlinePlus health-topic page, because none currently exists for maca.

There is no established standard dose. Products are sold as root powders and capsules with widely varying strengths, and a well-defined effective dose has not been determined. Because the evidence is limited and dosing is not standardized, talk to a doctor or pharmacist before starting maca, especially if you have a health condition, take medications, or are pregnant or breastfeeding.

As a food, maca appears generally well tolerated in the small studies done so far, but its safety has not been rigorously established, and its safety during pregnancy or breastfeeding is unknown. People with hormone-sensitive conditions, including certain breast, uterine, ovarian, or prostate cancers, should talk with their healthcare provider before using maca, as it could affect treatment. Maca may also interfere with the accuracy of testosterone laboratory tests.

Serious side effects have generally not been reported in the limited research, but some users have described changes to their menstrual cycles, mood changes, cramps, stomach upset (gastritis), and trouble sleeping. A single case report described prolonged bleeding between menstrual periods along with elevated testosterone in a woman taking maca daily. Because so few people have been studied, the full side-effect profile is not well understood.

Information on drug interactions in people is limited. In animal studies, maca appeared to add to the blood-pressure-lowering effect of the medication losartan, but whether this matters in humans is unknown. Tell your clinician about every supplement you take so they can check for possible interactions.