Quick answer

Maca root is an Andean food sold as a powder or extract. Small trials of 1.5 to 3.5 g a day looked at mood, energy and discomforts after menopause, and the evidence for each is graded early: reviews call it limited. Testosterone did not change in the trials that measured it.^1,2,3

Key facts

Maca is a root of the mustard family grown above about 4,000 m in the Peruvian Andes, where people cook it, bake it or make it into porridge.^4,5
Trials gave adults 1.5 to 3.5 g a day, usually for 6 to 12 weeks.^6,7
In healthy men, 12 weeks of maca did not change testosterone, estradiol, LH, FSH or prolactin.³
LiverTox rates maca an unlikely cause of liver injury, and the side effects it lists are uncommon and mostly mild.⁴

What maca is

Maca (Lepidium meyenii) is a root of the mustard family that grows above about 4,000 m in the Peruvian Andes.⁴

People in the Andes have grown and eaten maca for well over a thousand years. It reached the global market only in the last few decades, and it is now farmed in China as well, which a 2018 review warns may change the plant's chemistry and quality.⁵

In the Andes, maca root is eaten as a food: cooked, baked, made into porridge or fermented into a drink.⁵

The root is mostly carbohydrate and protein, and it also contains iron and calcium.⁴

Besides carbohydrate and protein, the root holds compounds found only in maca, called macamides and macaenes, and glucosinolates, compounds typical of the mustard family it belongs to. Researchers credit these with maca's effects, but the same review says there is not enough data to confirm it.^4,5

What the evidence shows

Every maca benefit below is graded early. That means a handful of small trials, often testing different products at different amounts, and reviews that call the evidence limited. Each claim shows the daily amount the studies used.^1,6

May support self-rated mood and energy*²

Early evidence

One randomized trial gave 175 adults in Peru 3 g a day of red or black maca extract or a placebo for 12 weeks. Among those living at low altitude, more people on either maca rated their mood higher from week 1 and their energy higher from week 2. Among highlanders, mood on red maca differed from placebo only in the first month. Each outcome was a single self-rated question, and one of the authors manages a company that makes nutraceuticals.

Amount studied: 3 g a day of red or black maca extract, for 12 weeks

May ease some self-rated discomforts after menopause*^1,7,8

Early evidence

A 2011 review found four small randomized trials in women around or after menopause. All reported better scores on menopause rating scales with maca, but the reviewers judged the trials too few, too small and too weak for firm conclusions. The largest trial we found, of a branded gelatinized maca at 2 g a day in 168 women, reported fewer hot flashes and night sweats. In a smaller crossover trial, 14 women taking 3.5 g of maca powder a day for 6 weeks scored lower for psychological discomfort and sexual concerns than on placebo.

Amount studied: 2 to 3.5 g a day of maca powder, for 6 weeks to 4 months

LiverTox notes that none of the effects claimed for maca has been proven in prospective, rigorously controlled trials in people.⁴

For men: testosterone, sperm and exercise

Maca is often sold to men as a way to raise testosterone. The trials do not back that up.^3,9

In healthy men, 1.5 or 3 g a day for 12 weeks did not change testosterone, estradiol, LH, FSH or prolactin compared with placebo.³

A 2024 review of 52 studies of supplements sold to raise testosterone found that most did not, and maca was not among the few that did.⁹

In a 2022 pooled analysis of randomized trials, maca did not change sperm concentration significantly compared with placebo, and other sperm measures gave mixed results.¹⁰

Exercise trials are few and small. In 10 trained basketball players, 2 g a day for 2 weeks did not change jump height, shooting accuracy, repeated sprints or fatigue compared with placebo.¹¹

Hormones and body weight

Two trials in women after menopause found no change in estradiol, FSH or LH at 3.3 to 3.5 g a day for 6 weeks. Trials of one branded gelatinized maca reported higher estradiol and lower FSH.^7,8,12

In 80 men over 40, 12 weeks of gelatinized maca did not change total or free testosterone, body weight or waist size compared with placebo.¹³

We found no trial that set out to test maca for gaining weight. In a 12-week trial in men that tracked weight, it rose slightly on placebo too, so maca was not the cause.¹³

How much people take

Trials gave adults 1.5 to 3.5 g of maca a day, as tablets, capsules, powder or extract, usually for 6 to 12 weeks.^2,6,7

Recommended daily amounts on maca products vary widely, from about 500 to 3,000 mg, depending on the preparation.⁴

Plain powder, gelatinized powder and extracts were all tested at roughly the same 1.5 to 3.5 g a day, so a gram of one is not a known match for a gram of another. The dosage guide sets the trial amounts side by side.^2,6

Forms and colors

Dried root that is rehydrated, briefly put under pressure while moist and dried again. This breaks down the starch and makes it easier to digest. It is the form used in most trials in men, at 1.5 to 3 g a day.^6,14

Concentrated extracts, such as the spray-dried red and black maca extracts given at 3 g a day in a 2016 trial. Extracts differ from maker to maker, so a result for one does not carry over to another.²

Maca roots vary in color, mainly yellow, red and black. In one trial, red and black extracts differed in their chemistry, and red gave larger changes in self-rated mood and energy.^2,4

What's in ours

What’s in ours

Ashwagandha Complex: Maca Root Powder, 150 mg per serving, from the label

Ashwagandha Complex lists 150 mg of maca root powder per serving. Trials used 1.5 to 3.5 g a day, at least ten times as much, so we make no maca claim for it.^6,7

Side effects, and who should ask first

Side effects reported with maca are uncommon and usually mild, mostly stomach upset and headache.⁴

LiverTox rates maca an unlikely cause of liver injury. It describes one published case of jaundice in a man who drank 300 mL of a maca liquor, which cleared over 1 to 3 months.⁴

In a 90-day trial in adults with metabolic syndrome, 0.6 g of maca powder a day moderately raised the liver enzyme AST and diastolic blood pressure.¹⁵

No safe upper amount has been set for maca. Trials used up to 3.5 g a day, mostly for 12 weeks or less, and a 2011 review noted that its safety had not been proven.^1,6,7

FDA told consumers in 2019 not to buy or use a product sold as Peru Maca, after its laboratory found sildenafil, a prescription drug ingredient, that was not on the label.¹⁶

Ask your doctor first if you are pregnant or breastfeeding: maca's safety has not been studied at these times¹
Ask first if you take a prescription medicine, including an antidepressant, hormonal birth control or a medicine for blood pressure
Ask first if you have liver disease or high blood pressure¹⁵
Ask first if you have a hormone-sensitive condition, since trials of one branded maca reported changes in estradiol and FSH⁸

The official sources we checked, including LiverTox, MedlinePlus and drug labels, do not name a medicine that interacts with maca. That is a gap in the evidence, not proof of safety. If you take any prescription medicine, ask your pharmacist before starting.^4,17

Questions people ask

Does maca raise testosterone?

Not in the trials that measured it. In healthy men taking 1.5 or 3 g a day for 12 weeks, testosterone and other reproductive hormones stayed the same as on placebo, and a 2024 review of supplements sold to raise testosterone did not count maca among the few that do.^3,9

Does maca help you gain weight?

There is no evidence that it does. In a 12-week trial in 80 men, weight and waist size changed the same way on maca as on placebo, and we found no trial designed to test weight gain.¹³

Is red, black or yellow maca better?

There is too little research to say. In the one trial that compared two colors, red and black extracts differed in their chemistry, and red maca gave larger changes in self-rated mood and energy.²

Is it safe to take maca every day?

In trials lasting up to about 3 months, side effects were uncommon and mostly mild, such as stomach upset. Safety beyond that has not been studied, no safe upper amount has been set, and anyone pregnant or breastfeeding should ask a doctor first.^1,4

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Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.