What Is Maca Root Good For? What the Trials Measured

Maca is the dried root of a Peruvian plant in the cabbage family, eaten as food in the Andes and not a novel food in Great Britain. Against placebo, desire rose from week 8 in 57 men, erection scores rose in 50 men, ageing-symptom scores fell in 80 men over 40, and mood and energy improved with black and red extract in 175 adults; testosterone did not rise in four trials, and two pooled sperm trials showed no significant difference.^{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

The 80-man and 175-adult trials were publicly funded (three authors of the first list company affiliations; one author of the second runs a small nutraceutical company); the 57-man desire and 50-man erection abstracts do not state funding. Maca has no authorised health claim in Great Britain,¹¹ and the NHS sends worries about low sex drive or getting pregnant to a GP first.^{12, 13}

Evidence at a glance

• Trials: 14 placebo-controlled trial reports cited here (8 to 175 people each), a 2022 review of 5 sperm trials (2 pooled) and a 2011 review of 4 menopause trials.
• Largest single trial: 175 adults in Peru took 3 g of black or red maca extract or placebo daily for 12 weeks.
• Strongest measured outcome: in 80 men over 40, ageing-male symptom scores fell 10.66 points on about 5 g of gelatinised maca a day over 12 weeks, more than on placebo (publicly funded).
• Not tested: whether maca changes pregnancy or live-birth rates.

Sources checked on 14 October 2026.

What is maca, and how do people eat it?

Maca is Lepidium meyenii, also listed as Lepidium peruvianum, a plant of the cabbage and mustard family grown at 4,000 to 4,500 metres in the central Andes of Peru.^{1, 2} The part eaten is a radish-like root, dried until hard as stone and boiled before eating, most often as a drink; highland diets include more than 20 g of dried root a day. Dried maca is about 59% carbohydrate, 10% protein, 8.5% fibre and 2% fat.¹

Maca is sold as powder, gelatinised powder, capsules and extracts; the powder goes into porridge, smoothies, yoghurt or warm milk. No trial has compared ways of taking it; the table below gives the amounts and lengths trials used. Maca is often called a "superfood", a label with no agreed definition; a 2018 review of such foods found one controlled maca trial on metabolic measures.¹⁴ For colours and gelatinising, see black, red and yellow maca.

What does maca do to the body?

Trials have mostly measured questionnaire scores: desire, erections and sperm in men, menopause and mood in women, energy in mixed groups. Single small trials mostly favoured maca; two pooled sperm trials showed no significant difference.¹⁰

For low sex drive, the NHS lists causes including "stress, anxiety or depression" and medicines "such as medicine for high blood pressure or antidepressants", and advises seeing a GP if worried.¹² A PubMed search on 13 October 2026 found no human trial of maca for skin or acne.

Does maca change testosterone, oestrogen or other hormones?

Not in the men's trials that measured them. Testosterone did not rise against placebo in four trials of 12 to 16 weeks, in healthy men, men with fertility problems and men over 40; free testosterone fell in the 50-man fertility trial, and LH, FSH, prolactin and oestradiol did not change in men aged 21 to 56.^{5, 7, 8, 9} The rise in desire in the 57-man trial was independent of testosterone.³

In women, oestradiol, FSH and SHBG did not change in 14 or in 29 postmenopausal women, nor did thyroid-stimulating hormone in the 29.^{19, 20} One supplier-linked programme reported lower FSH and higher LH in early-postmenopausal women, and higher oestradiol and progesterone after eight months in 8 of them.²¹ No trial cited here measured cortisol or periods. In one UK case report, a woman taking maca extract had a testosterone result of 25.8 nmol/L on one laboratory test and 2.9 nmol/L on a more specific one,²² so tell the GP or laboratory what you take before a hormone test.

Can maca help energy, mood or exercise?

Mood and energy scores improved in the largest trial. In 175 adults in Peru, 3 g a day of black or red maca extract for 12 weeks improved mood, energy and health-status scores against placebo, mood and energy more with red (publicly funded; one author runs a small nutraceutical company).⁶ Anxiety and depression scores fell against placebo in 14 postmenopausal women, and depression scores fell after the maca weeks in 29.^{19, 20}

Exercise results are mixed: no difference from placebo in cyclists' time trials or basketball players' jumping, shooting and sprinting, and one immune marker higher after hard exercise in 20 men.^{15, 17, 18} Trials recorded questionnaire changes after 2 to 12 weeks, not same-day effects; maca side effects and how much to take covers timing.

Can maca help you get pregnant?

No trial has measured pregnancy or live births as an outcome of taking maca. The NHS says: "You're also advised not to take herbal remedies if you're trying to get pregnant."²³ In 69 men with mildly low sperm counts or movement, 2 g a day for 12 weeks gave a higher sperm concentration than placebo (15.0 against 10.2 million per mL), with no difference in movement or shape; in 50 men with fertility problems, 2.8 g of yellow maca for 16 weeks made no significant difference; and a 2022 review pooling two trials found no significant difference.^{9, 10, 24}

NICE advises telling people concerned about their fertility "that the effectiveness of complementary therapies for fertility problems has not been properly evaluated, and that further research is needed before such interventions can be recommended".²⁵ The NHS suggests seeing a GP after a year of trying, and sooner for women aged 36 and over.¹³ No amount of maca has been tested for conception.

What does maca do for women?

A 2011 review found four small randomised trials for menopause symptoms, all favourable; it called the evidence limited and said safety had not yet been proved.¹⁶ In 14 postmenopausal women, sexual-dysfunction and psychological symptom scores fell against placebo without hormone changes.¹⁹ In 45 women whose antidepressants had caused sexual side effects, 3 g of maca root a day for 12 weeks gave remission in 9.5% against 4.8% on placebo, more often after the menopause (publicly funded).²⁶

The NHS lists HRT among treatments when low sex drive follows the menopause, and sends low desire to a GP first.¹² The menopause trials compared maca with placebo, not with HRT. Whether libido supplements for women work and which menopause supplements have evidence set out the wider picture.

Which form of maca: powder, capsules, gelatinised or extract?

Every form starts as the same dried root; powder is that root milled, and no trial has compared forms in people. Gelatinised maca has been rehydrated, briefly put under raised pressure while moist to break down its starch, and dried again.⁸ An extract concentrates the root; its label may give a ratio or an "equivalent to" figure, which is the weight of dried root the extract was made from, not the weight of maca in the capsule, and ratios differ between products. Capsules and gummies carry any of these. Trials used 3 to 3.5 g of root powder, 1.5 to about 5 g of gelatinised root and 2.4 to 4.5 g of extract a day.^{3, 4, 5, 18, 19, 26} Black, red and yellow maca explains extract strengths, and maca side effects and how much to take the amounts.

Is maca safe?

In trials of up to 16 weeks, recorded side effects were few and mostly mild. In the 80-man trial, two men had mild stomach upsets and carried on, and blood tests, urine, vital signs and PSA did not change; in the 50-man fertility trial, two left for possible side effects (starch intolerance and a new bowel diagnosis); maca was well tolerated in 45 women; and the 175-adult trial recorded no serious side effects.^{5, 6, 9, 26} The US liver-injury reference LiverTox says maca "has not been implicated in causing liver injury".²⁷

A pharmacist can check maca against any medicine you take. Maca grown near mining areas in Peru has carried cadmium and lead above international food limits, so products batch-tested for heavy metals are the ones to look for.²⁸

What may a UK label say about maca?

Maca has no authorised health claim on the Great Britain register.¹¹ Wordings submitted for maca, on energy, physical and mental performance, stamina and vitality, on sexual activity and desire, on fertility, and on bone health at the menopause, sit on the gov.uk list of "on hold" claims, which "may continue to be used in Great Britain" while they remain under consideration.²⁹ An on-hold wording has not been assessed and is not an authorised claim. Where a product adds vitamins or minerals, their authorised wordings belong to those nutrients, not to the maca.¹¹

Maca root is not a novel food: the EU novel food catalogue records that member states agreed in 2001 to 2003 not to treat the root as novel, and EU novel-food decisions made before 1 January 2021 still apply in Great Britain.² No UK traditional herbal registration exists for maca.³⁰

Every guide in this series

• Maca for men: desire, erections, sperm and testosterone.
• Black, red and yellow maca: colours, gelatinised maca and extract strengths.
• Maca side effects and how much to take: what trials recorded and used.
• Do libido supplements for women work? Maca and other botanicals.
• What is ginseng good for? A different plant, its own trials.
• What is ginkgo biloba good for? Memory trials and safety.
• The Wellgard ashwagandha guide: stress, sleep, men and women.
• Supplements for men: each goal with its NHS route.

What we don't know

• Whether any effect lasts: most trials ran 2 to 16 weeks, and the longest, a supplier-linked programme, gave 8 women maca for eight months of a nine-month programme.²¹
• Whether colours or forms differ: one trial compared black with red extract; none has tested yellow, gelatinised or raw maca against another.⁶
• Whether maca changes pregnancy or live-birth rates: no trial has measured either.
• Interactions with medicines: we found no published interaction trial in people.
• Whether results hold in larger groups: most trials are small and from a few research groups.

Frequently asked questions

Is maca the same as ginseng?

No. Maca is sometimes called "Peruvian ginseng",⁵ but ginseng is a different plant with its own trials, cautions and UK traditional herbal registrations, set out in what ginseng is good for.

Is maca better than ashwagandha?

No trial has compared the two, so neither can be ranked. Maca's trials measured desire, mood and menopause questionnaires in small groups; ashwagandha's measured stress, cortisol, sleep and testosterone, set out in the Wellgard ashwagandha guide. No trial has tested them together.

Can maca change your body shape or make you gain weight?

No trial has measured hips, bust or body shape. In the 80-man trial, body weight and waist rose on both maca and placebo over 12 weeks, with no difference between groups.⁵ By the composition figures above, 3 g supplies roughly 9 kcal.¹

What does maca taste like?

It is commonly described as earthy and nutty. In the 175-adult trial, 0% to 4% of people disliked the taste of the spray-dried extracts.⁶

Sources

1. Gonzales GF. Evidence-Based Complementary and Alternative Medicine 2012. Review; publicly funded; the author later declared a nutraceutical business; figures from the full text. PubMed 21977053
2. Food Standards Agency. Novel foods authorisation guidance, 30 May 2018, citing the EU Novel Food Status Catalogue (maca root: not novel; entry modified 16 January 2026). gov.uk/government/publications/novel-foods-authorisation-guidance
3. Gonzales GF et al. Andrologia 2002. Randomised trial, 57 men, 12 weeks; funding not stated in the paper's abstract. PubMed 12472620
4. Zenico T et al. Andrologia 2009. Randomised trial, 50 men, 12 weeks; funding not stated in the paper's abstract. PubMed 19260845
5. Shin D et al. World Journal of Men's Health 2023. Randomised trial, 80 men, 12 weeks; publicly funded; three authors list company affiliations; some figures from the full text. PubMed 36593713
6. Gonzales-Arimborgo C et al. Pharmaceuticals 2016. Randomised trial, 175 adults, 12 weeks; publicly funded; one author runs a small nutraceutical company. PubMed 27548190
7. Gonzales GF et al. Journal of Endocrinology 2003. Randomised trial, men aged 21 to 56, 12 weeks; size and funding not stated in the abstract. PubMed 12525260
8. Melnikovova I et al. Evidence-Based Complementary and Alternative Medicine 2015. Randomised pilot, 20 men, 12 weeks; maca supplied by a Peruvian producer; no funding statement. PubMed 26421049
9. Melnikovova I et al. Phytotherapy Research 2021. Randomised trial, 50 men, 16 weeks; university-funded; maca supplied by a Peruvian producer. PubMed 34585449
10. Lee HW et al. Frontiers in Pharmacology 2022. Systematic review of 5 randomised trials, two not peer reviewed, 2 pooled; doses and pooling from the full text. PubMed 36110519
11. Department of Health and Social Care. Great Britain nutrition and health claims register, last updated 19 May 2026. gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register
12. NHS. Low sex drive (loss of libido). Page last reviewed 26 May 2026. nhs.uk/conditions/loss-of-libido
13. NHS. Infertility. Page last reviewed 9 August 2023 (review overdue). nhs.uk/conditions/infertility
14. van den Driessche JJ et al. Food & Function 2018. Systematic review of 113 trials of 17 foods, 1 of maca. PubMed 29557436
15. Stone M et al. Journal of Ethnopharmacology 2009. Randomised crossover, 8 men, 14 days each; funding not checked (no open full text). PubMed 19781622
16. Lee MS et al. Maturitas 2011. Systematic review of 4 randomised trials. PubMed 21840656
17. Wu PS et al. Journal of Physiological Investigation 2025. Randomised crossover, 10 men, 2 weeks each; funding not checked. PubMed 40960048
18. Weng PW et al. International Journal of Medical Sciences 2025. Placebo-controlled matched-pair trial, 20 men, 12 weeks; publicly funded. PubMed 39781531
19. Brooks NA et al. Menopause 2008. Randomised crossover, 14 women, 6 weeks each; a US public research grant is listed. PubMed 18784609
20. Stojanovska L et al. Climacteric 2015. Randomised crossover, 29 women, 6 weeks each; funding not checked. PubMed 24931003
21. Meissner HO et al. International Journal of Biomedical Science 2005. Placebo-corrected pilot, 20 women for 3 months, 8 for eight months of maca in a nine-month programme; supplier-linked: the lead author's company co-funded it and a maca supplier shared the batch costs. PubMed 23674952
22. Srikugan L et al. BMJ Case Reports 2011. Case report, 1 woman. PubMed 22700073
23. NHS. Medicines in pregnancy. Page last reviewed 5 September 2022 (review overdue). nhs.uk/pregnancy/keeping-well/medicines
24. Alcalde AM, Rabasa J. Andrologia 2020. Randomised trial, 69 men, 12 weeks; funding not stated in the paper's abstract. PubMed 32654242
25. NICE. Fertility problems: assessment and treatment (NG257), 1.14.1, published 31 March 2026. nice.org.uk/guidance/ng257
26. Dording CM et al. Evidence-Based Complementary and Alternative Medicine 2015. Randomised trial, 45 women, 12 weeks; publicly funded. PubMed 25954318
27. LiverTox: Maca. US National Institutes of Health. Reference entry, last updated 10 April 2019. PubMed 31643869
28. Orellana Mendoza E et al. Toxicology Reports 2021. Field study of maca grown near mining areas in Peru. PubMed 34401355
29. Department of Health and Social Care. 'On hold' health claims on foods (spreadsheet), last updated 12 January 2021. gov.uk/government/publications/on-hold-health-claims-on-foods
30. MHRA. Herbal medicines granted a traditional herbal registration, list last updated 28 October 2025. gov.uk/government/publications/herbal-medicines-granted-a-traditional-herbal-registration-thr

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