Red, Yellow, and Black Maca: What the Research Shows About Benefits, Differences, and Safety

Maca is a root vegetable from the high Andes of Peru that has become one of the most popular superfood powders and supplements in the world. It is sold for energy, libido, fertility, mood, and menopausal symptoms, and increasingly by color: yellow maca for general use, red maca for prostate and bone health, black maca for energy, memory, and male fertility. Product pages often present these differences as established science.

The research on maca is real and growing, but much of it is small, short-term, or done in animals, and the evidence for color-specific benefits comes mostly from laboratory and rodent studies. This article reviews what maca is, what human clinical trials have found, how red, yellow, and black maca differ, what is known about safety, and how to choose and use maca sensibly.

What is the difference between red, yellow, and black maca? They are color variants of the same root grown in Peru. Yellow is the most common and general-purpose; red maca has the most evidence for prostate and bone health and mood; black maca is studied most for energy, stamina, and male fertility. All may support energy and hormonal balance, but human evidence is limited and the color differences are based on small studies.

What Maca Is

Maca, Lepidium meyenii, is a member of the Brassicaceae family, which also includes broccoli, cabbage, and radishes. It grows on the high plateaus of the central Peruvian Andes, especially around Junín, at altitudes above about 4,000 meters, where few other crops survive the cold, wind, intense sunlight, and poor soils. The part used is the hypocotyl, a swollen root-like structure that looks somewhat like a small turnip.

Andean communities have eaten maca for centuries. A review by Gustavo Gonzales of Universidad Peruana Cayetano Heredia, one of the most prolific maca researchers, describes its traditional use as a food, typically dried and then boiled, roasted, or ground into flour for porridges, drinks, and baked goods, and as a remedy believed to support fertility and vitality, including in livestock raised at high altitude.

Maca is nutritious as a food. It provides carbohydrates, protein, fiber, and minerals, along with compounds characteristic of the plant, including glucosinolates, which are common in the cabbage family, and unique compounds called macamides and macaenes. Researchers have explored these compounds as possible contributors to maca’s effects, but which compounds are responsible for any benefits remains uncertain.

What Do the Maca Colors Actually Mean?

Red, yellow, and black maca are natural color variants of the same Peruvian root; the colors reflect different pigments and slightly different compound profiles, which small studies link to somewhat different effects. Maca plants produce hypocotyls in a range of colors, from cream and yellow to red, purple, gray, and black. Farmers and researchers commonly group them into three main types. Yellow maca is the most common in harvests. Red and black are less common and often sold at higher prices.

The colors reflect differences in pigment and in the concentrations of some compounds. Some studies have found that different colors contain different amounts of certain glucosinolates, polyphenols, and other constituents, though composition also varies with growing location, season, and processing. Most of the research suggesting different biological effects by color comes from experiments in rats and mice conducted by a small number of research groups, particularly in Peru.

For red maca, studies in rats have found that extracts reduced prostate size when prostate enlargement was induced experimentally with hormones. A 2020 study in Andrologia from the Gonzales group examined inflammatory pathways involved in red maca’s effect in rats with induced benign prostatic hyperplasia. For black maca, rodent studies have reported effects on sperm production and on learning and memory tasks. These findings are interesting starting points but cannot be directly translated into recommendations for people, since animal doses, preparations, and conditions differ from human use.

Does Maca Actually Work?

Some small human trials suggest maca may improve energy, mood, and sexual function and ease some menopausal symptoms, but the evidence is limited, and larger, higher-quality studies are needed to confirm benefits. Human research on maca consists mainly of small randomized, placebo-controlled trials lasting six to twelve weeks. The most consistent findings involve sexual desire and symptoms around menopause.

Sexual desire in men

A 2002 randomized trial in Andrologia by Gonzales and colleagues gave healthy men aged 21 to 56 either maca at 1.5 or 3 grams per day or placebo for 12 weeks. Men taking maca reported improved sexual desire beginning at eight weeks. Importantly, blood levels of testosterone and estradiol did not differ between the maca and placebo groups, and the effect was not explained by changes in depression or anxiety scores. This finding, that maca does not appear to work by raising testosterone, has been echoed in other studies.

Sexual function: what systematic reviews say

A 2010 systematic review in BMC Complementary and Alternative Medicine by Byung-Cheul Shin and colleagues identified a small number of randomized trials of maca for sexual function. Some showed significant positive effects on sexual desire or sexual dysfunction. The authors concluded that the results provided limited evidence for maca’s effectiveness, because the number of trials, total sample size, and methodological quality were too limited to draw firm conclusions.

Antidepressant-related sexual dysfunction

A 2015 double-blind, placebo-controlled trial by Christina Dording and colleagues at Massachusetts General Hospital tested maca root at 3 grams per day for 12 weeks in women experiencing sexual dysfunction caused by antidepressants. More women in the maca group than in the placebo group reached the trial’s targets for improved sexual functioning, with benefits appearing more pronounced in postmenopausal women, though the overall differences were modest and the study was small.

Menopausal symptoms and mood

A 2008 crossover trial in Menopause by Nicole Brooks and colleagues gave postmenopausal women 3.5 grams of maca per day for six weeks and placebo for six weeks, in random order. Maca reduced psychological symptoms, including anxiety and depression, and lowered measures of sexual dysfunction compared with placebo. Hormone levels, including estradiol and follicle-stimulating hormone, did not change significantly, suggesting the effects did not come from estrogen-like activity.

A 2015 pilot study in Climacteric by Lily Stojanovska and colleagues in 29 postmenopausal Chinese women in Hong Kong used a similar crossover design with 3.3 grams per day for six weeks. It found significant decreases in diastolic blood pressure and depression scores after maca treatment compared with placebo.

A 2011 systematic review in Maturitas by Myeong Soo Lee and colleagues identified four randomized trials of maca for menopausal symptoms. All showed favorable effects, but the authors noted there were very few rigorous trials and that the total number of trials, sample sizes, and study quality were too limited to draw firm conclusions.

Energy, mood, and athletic performance

Maca is widely marketed for energy and stamina. A few small studies have explored effects on mood, energy, and exercise performance, with mixed and preliminary results. There is not enough evidence to conclude that maca reliably improves energy or athletic performance in healthy people.

Fertility

Interest in maca for fertility comes from traditional use and from animal studies showing effects on sperm production. Small human studies have looked at semen parameters in healthy men with mixed results. There is not enough evidence to recommend maca as a fertility treatment, and people trying to conceive should discuss supplements with their healthcare provider.

How Does Maca Work in the Body?

Maca does not contain hormones but may act as an adaptogen affecting the body’s stress and hormonal systems; its exact mechanisms are not well understood and remain under study. Because studies have generally found no changes in testosterone, estrogen, or other sex hormone levels, researchers have proposed that maca acts through other mechanisms. Hypotheses include effects on the brain’s signaling pathways involved in mood and sexual desire, antioxidant and anti-inflammatory activity, and actions of maca’s distinctive compounds, the macamides, some of which interact with the endocannabinoid system in laboratory studies. Extracts have shown estrogen-like activity in some cell experiments, but human trials have not shown corresponding hormonal changes. None of these mechanisms has been confirmed in people.

Is Maca Safe to Take?

Maca is generally considered safe as a food and supplement for most people, with occasional mild digestive effects, though those with thyroid or hormone-sensitive conditions should consult a clinician. Maca has a long history of use as a food in the Andes, and in clinical trials at doses of about 1.5 to 3.5 grams per day for up to roughly 12 weeks, it has generally been well tolerated, with side effects similar to placebo. Some people report digestive upset, and some report changes in sleep or mood.

Memorial Sloan Kettering Cancer Center’s integrative medicine guide advises people with hormone-sensitive cancers, such as breast or uterine cancer, to talk with their healthcare provider before using maca, because it may affect treatment, and notes that maca may not be safe during pregnancy or breastfeeding. It also advises people to tell their provider if they took maca before lab tests that measure testosterone.

Several additional cautions apply. Long-term safety beyond a few months has not been well studied. Traditional Andean practice is to cook or dry maca rather than eat it raw, and many commercial products are “gelatinized,” meaning they are heated to remove starch, which may make them easier to digest. As with any supplement, quality and purity vary between brands, and products marketed with dramatic claims should be viewed skeptically.

Maca as a Food: Nutrition Basics

Before it was a supplement, maca was a staple food, and its nutritional profile reflects that. Dried maca root is mostly carbohydrate, with a meaningful amount of protein, around a tenth of its dry weight according to compositional analyses summarized by Gonzales, along with dietary fiber and small amounts of fat. It provides minerals such as potassium, calcium, and iron, and contains glucosinolates and plant sterols. A typical supplemental dose of a few grams adds only modest nutrition, but in traditional diets, where maca was eaten in larger quantities, it contributed meaningfully to energy and nutrient intake at high altitudes where few crops grow.

Maca Compared With Other Popular Supplements

Maca is often sold alongside other supplements marketed for libido, energy, or hormone balance, and it helps to know how the evidence compares. Ashwagandha, an Ayurvedic herb, has been studied in more randomized trials for stress and sleep, though its research base also has limitations. Tribulus terrestris is widely marketed for testosterone, but controlled studies have generally not found that it raises testosterone in men. Ginseng has been studied for erectile function and fatigue with mixed results. Maca’s distinctive finding is that it has shown modest effects on sexual desire without changing hormone levels. None of these supplements has evidence comparable to approved medications for specific conditions, and combinations marketed as hormone boosters add uncertainty about interactions and quality.

How Do I Choose a Good Maca Product?

Look for products that specify the maca color, use gelatinized maca for easier digestion, come from reputable brands with third-party testing, and clearly state the dose per serving. Species and part. Look for Lepidium meyenii root or hypocotyl.

Raw or gelatinized. Labels should say which. Gelatinized is often easier to digest.

Color. Single-color products should state the color; many products are blends.

Amount per serving. Compare with the 1.5 to 3.5 grams used in trials. Extracts may list a ratio, such as 10:1, which makes comparison with whole-root powder difficult.

Origin and testing. Information on country of origin and third-party testing for heavy metals and microbial contamination is a mark of a more transparent supplier.

Choosing and Using Maca

Forms. Maca is sold as raw powder, gelatinized powder, capsules, and liquid or concentrated extracts. Gelatinized maca has been heated to remove starch, which many people find easier to digest and which more closely resembles traditional preparation, since Andean communities typically cook maca. Extract products are concentrated and may not be equivalent to the whole-root powder used in most trials.

Dose. Most human trials used 1.5 to 3.5 grams per day of maca powder for six to twelve weeks. There is no established optimal dose, and higher doses have not been shown to be more effective.

Timing. Effects in trials, where they appeared, took several weeks to emerge. Maca is not a quick-acting stimulant like caffeine.

Color. Given the limited human evidence for color-specific effects, choosing a color mainly for its marketed benefits is not supported by strong evidence. Yellow or mixed maca was used in most human trials.

Quality. Choose products that identify the species and plant part, disclose whether the maca is raw or gelatinized, and ideally provide third-party testing for contaminants such as heavy metals and microbes. Be cautious with products promising dramatic effects on testosterone, sexual performance, or fertility.

In food. Maca powder has a malty, slightly nutty flavor and can be added to smoothies, oatmeal, baked goods, and hot drinks, much as it is used traditionally in porridges and beverages.

Traditional Preparation

In the Andes, maca hypocotyls are traditionally harvested and dried in the open air for weeks, which concentrates them and allows long storage. Dried maca is then boiled, often with milk or water to make a sweet porridge or drink, roasted, or ground into flour for breads and cakes. Fresh maca is rarely eaten raw. Some researchers have suggested that traditional drying and cooking may change the composition of certain compounds, which could matter for comparisons between traditional use and modern powders or extracts, though this has not been thoroughly studied.

What Better Maca Research Would Look Like

The current evidence base has clear gaps. More convincing research would use larger randomized trials with hundreds rather than dozens of participants, longer durations of several months or more, standardized maca preparations with known composition, comparisons of different colors and of raw versus gelatinized forms in humans, objective outcome measures alongside questionnaires, and independent funding. Studies in specific populations, such as men with low libido, women in perimenopause, or people with antidepressant-related sexual side effects, would clarify who might benefit. Until such research exists, maca is best viewed as a food-based supplement with promising but preliminary evidence.

Realistic Expectations

People who try maca should expect, at most, gradual and modest changes over several weeks rather than dramatic effects. Placebo responses in trials of sexual function and mood are substantial, which is one reason controlled trials are essential and why individual experiences vary. Keeping a simple record of symptoms before and during use, giving it six to twelve weeks at a consistent dose, and stopping if there is no benefit or if side effects occur is a sensible approach. Maca is not a substitute for medical evaluation of persistent low libido, fatigue, mood changes, or menopausal symptoms, which can have treatable underlying causes.

Maca for Men: What to Know

Most interest in maca among men centers on libido, sexual function, and fertility. The best evidence, from the 2002 Andrologia trial and related studies, suggests a modest increase in self-reported sexual desire after about eight weeks at 1.5 to 3 grams per day, without changes in testosterone. Products marketed as “testosterone boosters” that feature maca therefore make claims not supported by human research.

For erectile dysfunction, evidence is limited to small studies with mixed results. Erectile problems can be an early sign of cardiovascular disease, diabetes, or other conditions, so men experiencing them should see a healthcare provider rather than relying on supplements. For fertility, small human studies of semen quality have produced inconsistent findings, and men trying to conceive should discuss any supplement with their provider.

Maca for Women: What to Know

For women, research has focused on menopausal symptoms and sexual function. Small crossover trials in postmenopausal women have found reductions in anxiety, depression, and some measures of sexual dysfunction, without changes in estrogen or other hormones, and one pilot study also found lower diastolic blood pressure. A trial in women with antidepressant-related sexual side effects found modest benefits, particularly after menopause.

These findings are encouraging but preliminary. Menopausal symptoms can be significant, and effective treatments exist, including hormone therapy for appropriate candidates and several non-hormonal options. Women considering maca for menopausal symptoms should discuss it with a clinician, particularly if they have a history of hormone-sensitive cancer or other conditions that affect treatment choices.

Common Myths About Maca

“Maca is a natural hormone replacement.” Human trials have generally found no changes in estrogen, testosterone, or related hormones.

“Black maca is proven better for men and red maca for women.” These color-specific claims come mainly from animal studies; human comparisons are lacking.

“More maca works better.” Higher doses have not been shown to be more effective than those used in trials.

“Maca works within days.” In trials, effects appeared after several weeks.

“Because it’s a food, maca is safe for everyone.” It appears well tolerated in short trials, but safety in pregnancy, breastfeeding, and hormone-sensitive conditions has not been established.

Who Should Be Cautious

Pregnant or breastfeeding people: Safety has not been established; consult a healthcare provider.

People with hormone-sensitive conditions: Including breast, uterine, ovarian, or prostate cancer, endometriosis, or fibroids. Although human trials have not shown hormonal changes, laboratory studies suggest some extracts may have estrogen-like activity, and integrative medicine references advise discussing use with a clinician.

People taking medications: Few interactions have been documented, but research is limited. Tell your healthcare provider and pharmacist about any supplements you take.

People having hormone testing: Inform your provider if you use maca before tests measuring testosterone.

People with thyroid conditions: Maca contains glucosinolates, as do other cabbage-family vegetables, which in very large amounts can affect thyroid function in people with iodine deficiency. At typical doses this is unlikely to matter, but people with thyroid disease may wish to check with their provider.

From Andean Staple to Global Supplement

Maca’s journey from a regional crop to a global commodity has had economic effects in the Andes. Rising international demand in the 2000s and 2010s increased prices and incomes for some growers, but also brought price volatility, concerns about export of planting material, and competition as maca cultivation spread to other countries. Peru has promoted maca as a protected Andean crop. For consumers interested in supporting traditional producers, products that identify Peruvian origin and fair sourcing practices are one option.

The Bottom Line

Maca is a nutritious traditional food with a modest but growing body of research. Small trials suggest it may help with sexual desire and some menopausal mood symptoms without changing hormone levels, and it appears well tolerated over several weeks. Claims about color-specific benefits, testosterone boosting, fertility, and athletic performance rest mostly on animal studies or limited human data. People who want to try maca can reasonably do so at doses used in trials, with realistic expectations and attention to the cautions above.

How Supplements Like Maca Are Regulated

In the United States, maca is sold as a food or dietary supplement. Under the Dietary Supplement Health and Education Act of 1994, supplements do not require FDA approval before they are sold. Manufacturers are responsible for ensuring their products are safe and properly labeled, must follow current good manufacturing practices, and may not claim that a supplement diagnoses, treats, cures, or prevents a disease. They may make structure-function claims, such as supporting energy or libido, accompanied by a disclaimer that the FDA has not evaluated the statement.

This framework means quality varies between brands, and product claims are not evidence of effectiveness. Independent third-party testing programs, which verify that a product contains what its label says and is free of specified contaminants, help consumers identify more reliable products.

Questions to Ask Before Buying

What do I hope maca will do, and is there evidence for that use? Have I discussed persistent symptoms with a healthcare provider? Am I pregnant, breastfeeding, or managing a hormone-sensitive condition? Does the product identify the species, form, color, and amount per serving? Has it been tested by an independent laboratory? Am I prepared to try it for several weeks at a trial-level dose and stop if it does not help?

Frequently Asked Questions

What is the difference between red, yellow, and black maca?

They are color varieties of the same plant with some differences in chemical composition. Claimed differences in benefits, such as red maca for prostate health or black maca for memory and sperm, come mainly from rodent studies. Human evidence for color-specific effects is very limited.

Does maca increase testosterone?

Human trials have generally not found changes in testosterone or estrogen levels. Effects on sexual desire reported in some trials appear to occur through other mechanisms.

Does maca help with menopause?

Small randomized trials found reductions in psychological symptoms such as anxiety and depression and improvements in some measures of sexual function in postmenopausal women. Systematic reviews call the evidence promising but limited.

How much maca should I take?

Clinical trials typically used 1.5 to 3.5 grams per day for six to twelve weeks. There is no established optimal dose.

Is maca safe?

It appears generally well tolerated in short-term trials and has a long history as a food. People who are pregnant, breastfeeding, or have hormone-sensitive conditions should consult a healthcare provider first.

What is gelatinized maca?

Maca that has been heated to remove its starch, making it easier to digest for many people and more similar to traditional cooked preparations.

References

1. Gonzales GF. Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca), a Plant from the Peruvian Highlands. Evidence-Based Complementary and Alternative Medicine. 2012;2012:193496. PMID 21977053
2. Gonzales GF, Córdova 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(6):367–372. PMID 12472620
3. Shin BC, Lee MS, Yang EJ, et al. Maca (L. meyenii) for improving sexual function: a systematic review. BMC Complementary and Alternative Medicine. 2010;10:44. PMID 20691074
4. Brooks NA, Wilcox G, Walker KZ, et al. Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women are not related to estrogen or androgen content. Menopause. 2008;15(6):1157–1162. PMID 18784609
5. Lee MS, Shin BC, Yang EJ, et al. Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review. Maturitas. 2011;70(3):227–233. PMID 21840656
6. Stojanovska L, Law C, Lai B, et al. Maca reduces blood pressure and depression, in a pilot study in postmenopausal women. Climacteric. 2015;18(1):69–78. PMID 24931003
7. Dording CM, Schettler PJ, Dalton ED, 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;2015:949036. PMID 25954318
8. Vásquez-Velásquez C, Gasco M, Fano-Sizgorich D, Gonzales GF. Inflammatory pathway employed by Red Maca to treat induced benign prostatic hyperplasia in rats. Andrologia. 2020;52(3):e13516. PMID 31989657
9. Memorial Sloan Kettering Cancer Center. Maca (About Herbs). mskcc.org

Last updated: October 1, 2026