Maca properties: what studies show about libido, menopause, and energy

Maca (Lepidium meyenii) grows on the Junín plateau in the Peruvian Andes, at an altitude of 4000-4500 m above sea level. It is sold as a root that regulates hormonal balance. Research tells a different and, in my opinion, more interesting story: in human trials measuring testosterone, estradiol, LH, and FSH, maca did not change any of these parameters. Yet, some participants reported increased sexual desire and improved mood. This article separates two things that marketing often conflates: what maca does in the body and what is merely attributed to it. We will go through specific trials with participant numbers, dosages, and durations, what has not yet been examined, and unanswered safety questions.

KEY INFORMATION
• In 57 healthy men, testosterone and estradiol did not differ from placebo, although desire increased from the 8th week (Gonzales et al., Andrologia, 2002).
• A review of four randomized trials included a total of 131 participants and speaks of limited evidence (Shin et al., BMC CAM, 2010).
• A meta-analysis of five trials did not confirm the effect of maca on sperm concentration (Lee et al., Frontiers in Pharmacology, 2022).
• A significant portion of the research comes from one center in Lima, and in some studies, the authors declare ties to manufacturers.

Czym jest maca i co zawiera?

Maca is a swollen root of a plant from the cabbage family, related to radishes and watercress, grown in the central Andes of Peru above 4000 m above sea level. The edible part is the hypocotyl, usually dried and ground into powder. Besides its nutritional value, maca contains two groups of compounds that you won't find in other cruciferous vegetables: macamides and macaenes.

Dried root contains 10-14% protein and is also a source of iron, potassium, and vitamin C. It also contains glucosinolates, just like broccoli or cabbage, and this component later comes up in questions about the thyroid. Maca has been cultivated on the Junín plateau for hundreds of years, initially as food, not as a supplement.

Macamides are N-benzylamides of long-chain fatty acids. In laboratory studies, they inhibit FAAH, the enzyme that breaks down endocannabinoids, which is why they are described as indirect modulators of this system (Vera-López et al., Neurology International, 2024). This is a hypothesis from cell and animal models. No human trial has shown that this is the pathway through which the effects reported in surveys occur.

Does maca change hormone levels?

No. In no human trial measuring hormones after maca administration was there a change. This applies to testosterone, estradiol, LH, FSH, prolactin, SHBG, and TSH. The claim about supporting hormones, which maca is marketed with in stores, has no backing in these measurements.

Najmocniejszy pojedynczy wynik pochodzi z pracy Gonzalesa i in. (Andrologia, 2002): 57 healthy men aged 21-56 years, 12 weeks, 1500 or 3000 mg daily. Testosterone and estradiol levels did not differ between groups, and regression analysis showed that the reported increase in desire was not due to hormones or mood changes. In postmenopausal women Brooks i in. (Menopause, 2008) they went a step further: they tested extracts of maca in a yeast reporter assay and found no estrogenic or androgenic activity even at very high concentrations.

The conclusion is twofold. Maca is neither a phytoestrogen nor a testosterone booster, so it will not replicate the effects sought after with those substances. However, if something improves for someone, it happens outside the hypothalamic-pituitary-gonadal axis.

Czy maca poprawia libido?

Probably yes, but the evidence is weak and comes from small trials. In a 12-week placebo-controlled study with healthy men, the difference in reported desire appeared after eight weeks, it was not present after four weeks, and it persisted until the end of the observation.

Systematic review Shina i in. (BMC Complementary and Alternative Medicine, 2010) gathered all randomized trials that existed at the time. There were four, with a total of 131 participants. Two were favorable, the third in men with mild erectile dysfunction also showed positive results, while the fourth, involving eight cyclists, did not show an advantage over placebo. The authors summarized this as limited evidence and noted that none of the trials described the method of randomization or allocation concealment. None systematically collected data on adverse effects.

There is still a thread that product descriptions are silent about. Most of the work on maca comes from one center in Lima, Universidad Peruana Cayetano Heredia, and in a later trial by the same group, the corresponding author declared that he runs a private company producing nutraceuticals (Gonzales-Arimborgo i in., Pharmaceuticals, 2016). This does not invalidate the results, but explains why independent replications are so needed.

Czy maca pomaga przy zaburzeniach seksualnych po antydepresantach?

This has been checked twice and the results are weak, although they trend in the same direction. In a larger trial, 45 women with medication-induced sexual dysfunction from the SSRI or SNRI group took 3 g of maca daily for 12 weeks. The remission rates were higher than with placebo, but the differences were in single percentage points.

Liczby z pracy Dording i in. (Evidence-Based Complementary and Alternative Medicine, 2015) they look like this: remission on the ASEX scale in 9.5% of women taking maca compared to 4.8% on placebo, and on the MGH-SFQ questionnaire in 30% versus 20%. The authors themselves noted that the higher remission rate was associated with postmenopausal status and that the trial was of a pilot nature. An earlier study by this team (CNS Neuroscience and Therapeutics, 2008) compared only two doses, 1.5 and 3 g, without a placebo arm, and was completed by 10 out of 20 participants.

This is still the only area where maca has data on patients taking medications. Too little to consider it a remedy for antidepressant side effects. Enough to mention it to your doctor if the issue concerns you and you are considering a change in treatment.

Does maca alleviate menopausal symptoms?

The evidence is insufficient to confirm this. The review Lee i in. (Maturitas, 2011) included four randomized trials and although all showed positive results on the Kupperman and Greene scales, the authors wrote that the sample size is too small for conclusions, and the safety of maca has not been demonstrated.

The core consists of two trials. Brooks et al. administered 3.5 g daily to fourteen postmenopausal women in a crossover design for 6 weeks and noted a decrease in the severity of psychiatric symptoms, including anxiety and depression, with unchanged estradiol, FSH, LH, and SHBG. Stojanovska i in. (Climacteric, 2015) they repeated this scheme in 29 women in Hong Kong with 3.3 g daily: diastolic pressure decreased and depression scores improved, while estradiol, FSH, TSH, SHBG, lipids, and glucose remained unchanged.

Since then, no larger trial has emerged to resolve the issue. The authors of the Hong Kong study themselves pointed out that the way climacteric symptoms are reported may vary culturally, which significantly affects the results with 29 participants. For women who cannot use hormone therapy, maca thus remains an unresolved option, not a proven alternative.

Does maca boost energy and improve performance?

There is no evidence for athletic performance. The only trial involving athletes included eight trained cyclists: after 14 days of supplementation, the time for 40 km improved compared to the baseline, but not compared to placebo (Stone i in., Journal of Ethnopharmacology, 2009). This one difference determines the interpretation of the entire result.

Interestingly, what came out in the same study beyond performance. Reported sexual desire improved both compared to baseline and compared to placebo. The largest human trial to date included 175 people living in the lowlands and in the Andes, administered 3 g of black or red maca extract for 12 weeks, and showed improvements in mood, energy, and quality of life.

Subjective energy is, however, not the same as measured performance. The well-being questionnaire responds to the participant's expectations, and the study from the Andes mainly measured such endpoints. It is worth noting the second result of this work: in individuals with excessively high hemoglobin at high altitude, the extract lowered its concentration, while in lowland residents, it did not change at all. Some effects of maca thus reveal themselves only under specific conditions.

Does maca affect male fertility?

A 2022 meta-analysis did not confirm this. After collecting five randomized trials, maca did not increase sperm concentration compared to placebo, and the authors described its effect on semen parameters as unclear (Lee i in., Frontiers in Pharmacology, 2022).

So where does the reputation of maca as a fertility aid come from? From a study Gonzalesa i in. (Asian Journal of Andrology, 2001), in which nine men took 1500 or 3000 mg daily for four months. Semen volume, sperm count, and motility increased, while LH, FSH, prolactin, testosterone, and estradiol remained unchanged. The problem is that the study had no placebo group or randomization, and nine individuals is too few to distinguish the effect of the preparation from the natural variability of semen parameters.

The Andean tradition indeed links maca with fertility, including in livestock. Science has not yet replicated this in controlled conditions. If andrological diagnostics show reduced semen parameters, the starting point remains determining the cause, not a supplement. We discuss more about choosing products for specific purposes in our post about suplementach na start.

Is maca safe and what can it interact with?

Maca is a traditional food and has performed well in clinical trials in terms of tolerance, but well tolerated is not the same as tested. A systematic review from 2011 stated outright that the safety of maca has not been demonstrated, and since then, there have not been large trials.

What is known. A review from 2024 (Frontiers in Pharmacology) summarizes that adverse effects are rare, and toxicity in preclinical models is low. In a trial involving 175 participants conducted over 12 weeks, no serious adverse events were reported. On the other hand, Shin and his team noted that none of the four previous randomized trials even attempted to systematically collect such data.

What is not known. There are no pharmacokinetic studies checking whether maca affects drug metabolism, so nothing can be responsibly said about interactions. For hormone-dependent cancers, data is lacking: the absence of estrogenic activity in a yeast test is an argument, but not a safety study in patients. There is also a lack of data during pregnancy and breastfeeding. The only TSH measurement in humans comes from Stojanowska's trial, and after six weeks of 3.3 g daily, it did not change in 29 women, which in the case of thyroid disease is too weak a premise to decide independently.

We noticed another thread that hardly appears in product descriptions. In maca samples from the Junín province affected by mining activities, the average concentrations of cadmium (0.32 mg/kg) and lead (0.20 mg/kg) exceeded FAO and WHO values, and the estimated cancer risk for arsenic and cadmium was above the tolerance threshold (Toxicology Reports, 2021). This is an argument for buying maca with heavy metal testing, not for giving it up. We raise similar questions about other products for women in the text about suplementacji po czterdziestce.

Frequently Asked Questions

Czy maca podnosi testosteron?

No. In a 12-week placebo-controlled trial involving 57 healthy men, testosterone and estradiol levels did not differ between maca and placebo (Gonzales et al., Andrologia, 2002). An earlier study by the same team also did not show changes in LH, FSH, or prolactin after four months of use.

Which maca is better: yellow, red, or black?

Color comparisons were mainly conducted on animals. Black maca performed best in a learning test on mice, while red maca was the only one to reduce prostate size in rats (Gonzales i in., Reproductive Biology and Endocrinology, 2005). In humans, black and red were compared in one trial involving 175 participants.

Ile macy stosowano w badaniach?

In human trials, doses ranged from 1500 mg to 3500 mg of powdered root or extract daily, most commonly around 3 g for 6 to 12 weeks. This describes what was studied, not a recommendation. None of these regimens have been established as a therapeutic dose.

How long did it take for effects to appear in studies?

In the study by Gonzales et al. (Andrologia, 2002), the difference from placebo in reported desire appeared only after 8 weeks, and there was none after 4 weeks. The trial with cyclists lasted 14 days and did not show an advantage over placebo in a performance test.

Can maca be combined with medications?

There are no pharmacokinetic studies examining whether maca affects drug metabolism, so nothing can be responsibly said about interactions. The lack of data is not the same as the absence of risk. If you are taking medications regularly, inform your doctor or pharmacist about the supplementation.

Who should not use maca?

There is a lack of safety data during pregnancy and breastfeeding, as well as with hormone-dependent cancers. The review by Lee et al. (Maturitas, 2011) explicitly stated that the safety of maca has not been demonstrated. In cases of thyroid disease and ongoing treatment, make the decision together with your doctor.

If you are looking for plant-based products, check out the section supplements. Check the composition, source of raw material, and contamination studies on the specific product's card.

This article is for informational and educational purposes and does not constitute medical advice. Before starting supplementation, consult your doctor, especially if you are taking medications regularly, are pregnant or breastfeeding, or have a chronic illness.

Author: Michał Waluk · Opublikowano: 2026-06-22 · Aktualizacja: 2026-08-08