Maca Root: What It Is, What's Been Studied and Who Should Avoid It (UK Guide)

Maca root is the radish-like root of Lepidium meyenii, a plant in the cabbage and mustard family grown 4,000 to 4,500 metres up in Peru's central Andes, where it was probably first farmed 1,300 to 2,000 years ago. It is sometimes sold as "Peruvian ginseng", but it is not related to ginseng, and it has no authorised health claims in the UK.

Key takeaways

• A root vegetable, not a ginseng. Grown in the high Andes and, since the late 1990s, in China. "Peruvian ginseng" is a marketing name, and no health claim for maca is authorised in Great Britain.
• The human research is small. A 2018 review from UCL School of Pharmacy concluded that the health claims for maca "cannot be fully supported from a scientific standpoint".
• Hormone-sensitive conditions and blood tests. We found no studies of maca in people with hormone-sensitive conditions, such as breast or womb cancer, so ask first. If you are having hormone blood tests, tell your doctor you take maca.
• Our Saffron Gummies are not for use in pregnancy, while trying to get pregnant or breastfeeding, or by under-18s, anyone with phenylketonuria (PKU) or prone to allergies, or anyone allergic to any ingredient, and not with an autoimmune condition or immunosuppressants unless your doctor agrees. With bipolar disorder, a thyroid, liver, kidney or hormone-sensitive condition, high calcium, an operation coming up or another long-term condition, or on any regular medicine, including antidepressants, blood thinners, blood pressure medication and prescribed vitamin D, ask your GP or pharmacist first.

From us: Our Saffron Gummies contain 2,000mg of maca root (from 200mg of a 10:1 extract) per two gummies. They also contain 300mg of saffron (from a 10:1 extract standardised to 3.5% crocin and safranal), 2,000mg of moringa leaf, 200mg of rhodiola, 100mg of L-theanine, 100mg of magnesium, 50 micrograms of vitamin D3, 50mg of spirulina extract and 5mg of black pepper extract. Vegan, £18.99 for 60 gummies (30 days), third-party lab tested.

Maca root at a glance

What is maca root?

Maca is related to turnips, cabbage, mustard and watercress. The part people eat is a radish-like hypocotyl, the swollen section between stem and root. It grows on the high plateau around Junín in central Peru, where it was probably domesticated 1,300 to 2,000 years ago, and the first written description of it dates from 1553.

After harvest, maca is traditionally dried outdoors for weeks until it is "hard as stone", then boiled before eating. Macamides, a group of compounds in maca, are essentially absent from the fresh root and form during this drying.

Since the late 1990s it has also been grown widely in China and promoted online as "Peruvian ginseng". It is not a ginseng: ginseng (Panax) belongs to a different plant family, Araliaceae.

What has been studied?

In people, the research is a small number of short trials. A 2018 review from UCL School of Pharmacy in London found they had "yielded inconclusive results", with weaknesses in method and sample size, and concluded that "the health claims of maca cannot be fully supported from a scientific standpoint". One example:

• Peru, 2016. 193 adults at low or high altitude started taking 3g a day of spray-dried red or black maca extract, or a placebo, for 12 weeks, double-blind. Funded by Peruvian public grants; one author manages a company that makes nutraceuticals.

No trial we found tested maca with saffron or tested our gummies, and the human research as a whole is too little to support a health claim.

How much do people take?

Maca is not a vitamin or mineral, so it has no Nutrient Reference Value (NRV), and no official upper level has been set for it. The amounts on record:

• In trials: mostly 1.5g to 3g a day of dried maca powder or extract, for up to 16 weeks.
• As food in the Andes: more than 20g a day of dried maca, boiled.

Our Saffron Gummies contain 2,000mg of maca root per two gummies, from 200mg of a 10:1 extract. The 2,000mg figure tells you how much root the extract was made from, not the extract's effect or contents. No trial we found used a 10:1 extract like ours or tested our gummies, and powders and extracts are made differently, so their weights cannot be compared like for like.

Side effects and who should avoid it

Contamination. A 2021 study of maca from mining areas in Junín, Peru, found average cadmium and lead levels above UN Food and Agriculture Organization and World Health Organization values. In a 2018 US case report, a woman's blood lead level rose after she started a maca root powder supplement and fell when she stopped.

Blood pressure and a liver enzyme. In a 90-day Czech safety trial in people with metabolic syndrome, those taking 0.6g of maca powder a day had moderate rises in diastolic blood pressure (the lower number) and AST, a liver enzyme. Trials have also measured blood sugar, but no study in people has tested maca with blood pressure or diabetes medicines.

Reported side effects. A summary by Memorial Sloan Kettering, a US cancer centre, lists people's own reports of changes to periods, moodiness, cramps, gastritis (stomach inflammation) and trouble sleeping.

Hormones and blood tests. We found no studies of maca in people with hormone-sensitive conditions, and Memorial Sloan Kettering says it is unclear how far maca may affect hormone levels in the blood. It advises anyone with a hormone-sensitive cancer, such as breast or womb cancer, to talk to their healthcare provider first. In a UK case report, maca extract was suspected of causing a falsely high testosterone result in a woman: 25.8 nmol/L on one test, but 2.9 nmol/L when the same sample was rechecked on a more specific one.

Do not take our Saffron Gummies if you:

• are pregnant, trying to get pregnant, breastfeeding or under 18
• are allergic to any ingredient, including moringa, rhodiola and spirulina
• have phenylketonuria (PKU) or are prone to allergies (for the spirulina)
• have an autoimmune condition or take immunosuppressants, unless your doctor agrees (for the spirulina)

Ask your GP or pharmacist first if you:

• have bipolar disorder, or take antidepressants or other mood medication (for the saffron and rhodiola)
• take blood thinners such as warfarin, aspirin or clopidogrel, blood pressure medication or diabetes medicine
• take digoxin, water tablets or epilepsy medicine such as phenytoin (for the vitamin D3 and rhodiola)
• have a thyroid condition or take thyroid medicine (for the moringa)
• have a liver condition (for the rhodiola)
• have, or have had, a hormone-sensitive condition, such as breast or womb cancer (for the maca)
• are having hormone blood tests: tell your doctor you take maca
• have high calcium in your blood or urine, high vitamin D levels, kidney problems or kidney stones, or sarcoidosis (for the vitamin D3)
• are prescribed vitamin D: the NHS says not to add other vitamin D or calcium supplements without your doctor's advice
• have an operation coming up or another long-term condition, or take any other regular medicine

We found no human studies of maca in pregnancy or breastfeeding.

Take no more than two gummies a day. They contain 50 micrograms of vitamin D3, so count any other vitamin D you take: the NHS adult maximum is 100 micrograms (4,000 IU) a day. If a new symptom appears, stop and speak to your GP or a pharmacist. Food supplements are not a substitute for a varied diet and a healthy lifestyle.

List prices, before any discount code, correct on 1 November 2026.

Frequently asked questions

What are the benefits of maca root?

Maca root has no authorised health claims in the UK. The human research is a small number of short trials, none of them on our gummies, and a 2018 review from UCL School of Pharmacy in London concluded that "the health claims of maca cannot be fully supported from a scientific standpoint". That is too little to support a health claim.

Is maca safe, and what are the side effects?

Some people should not take it, or should ask first. We found no human studies of maca in pregnancy or breastfeeding. Anyone with a hormone-sensitive condition, such as breast or womb cancer, or taking blood pressure or diabetes medicine should ask a GP or pharmacist first. Our Saffron Gummies are not for use in pregnancy, while trying to get pregnant or breastfeeding, or by under-18s, anyone with phenylketonuria (PKU) or prone to allergies, or anyone allergic to any ingredient, and not with an autoimmune condition or immunosuppressants unless your doctor agrees. With bipolar disorder, a thyroid, liver, kidney or hormone-sensitive condition, high calcium, an operation coming up or another long-term condition, or on any regular medicine, including antidepressants, blood thinners, blood pressure medication and prescribed vitamin D, ask your GP or pharmacist first. Memorial Sloan Kettering, a US cancer centre, lists people's own reports of changes to periods, moodiness, cramps, gastritis and trouble sleeping. In one 90-day trial, people taking maca powder had moderate rises in diastolic blood pressure (the lower number) and a liver enzyme, and some maca grown near Peruvian mines has contained cadmium and lead above UN Food and Agriculture Organization and World Health Organization values. If a new symptom appears, stop and speak to a GP or pharmacist.

Does maca affect hormones?

Maca has no authorised health claims in the UK, and Memorial Sloan Kettering, a US cancer centre, says it is unclear how far maca may affect hormone levels in the blood. We found no studies in people with hormone-sensitive conditions, so anyone with one, such as breast or womb cancer, should ask their doctor first. In a UK case report, maca was suspected of causing a falsely high result on a testosterone blood test, so anyone having hormone blood tests should tell their doctor they take maca.

Can you take maca when pregnant or breastfeeding?

We found no human studies of maca in pregnancy or breastfeeding, and Memorial Sloan Kettering, a US cancer centre, says it may not be safe then. Our Saffron Gummies are not for use in pregnancy, while trying to get pregnant or breastfeeding, or by under-18s, anyone with phenylketonuria (PKU) or prone to allergies, or anyone allergic to any ingredient, and not with an autoimmune condition or immunosuppressants unless your doctor agrees. With bipolar disorder, a thyroid, liver, kidney or hormone-sensitive condition, high calcium, an operation coming up or another long-term condition, or on any regular medicine, including antidepressants, blood thinners, blood pressure medication and prescribed vitamin D, ask your GP or pharmacist first. Ask your midwife, GP or pharmacist which supplements suit you.

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

They are colour types of the same plant, Lepidium meyenii. Thirteen colours, from white to black, have been recorded in one Andean district. In a 2016 Peruvian study, black maca extract had more macamides and red had more GABA, an amino acid. Most colour comparisons have been in rats, so claims that one colour suits women and another suits men are not backed by human trials. Our label does not name a colour.

References

1. Gonzales GF. "Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca), a Plant from the Peruvian Highlands." Evid Based Complement Alternat Med, 2012. doi:10.1155/2012/193496
2. Gonzales GF, Gonzales C, Gonzales-Castañeda C. "Lepidium meyenii (Maca): a plant from the highlands of Peru--from tradition to science." Forsch Komplementmed, 2009. doi:10.1159/000264618
3. Beharry S, Heinrich M. "Is the hype around the reproductive health claims of maca (Lepidium meyenii Walp.) justified?" J Ethnopharmacol, 2018. doi:10.1016/j.jep.2017.08.003
4. Esparza E et al. "Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices." Phytochemistry, 2015. doi:10.1016/j.phytochem.2015.02.030
5. GBIF Secretariat. "Lepidium meyenii Walp." and "Panax ginseng C.A.Mey." GBIF Backbone Taxonomy, checked 1 November 2026. gbif.org.
6. Gonzales-Arimborgo C et al. "Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii) in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study." Pharmaceuticals (Basel), 2016. doi:10.3390/ph9030049
7. Valentová K et al. "Maca (Lepidium meyenii) and yacon (Smallanthus sonchifolius) in combination with silymarin as food supplements: in vivo safety assessment." Food Chem Toxicol, 2008. doi:10.1016/j.fct.2007.10.031
8. Orellana Mendoza E et al. "Heavy metals in soils and edible tissues of Lepidium meyenii (maca) and health risk assessment in areas influenced by mining activity in the Central region of Peru." Toxicol Rep, 2021. doi:10.1016/j.toxrep.2021.07.016
9. Johnson-Arbor K et al. "Unintentional and Sequential Lead Exposure from a Ceramic Mug and Maca (Lepidium meyenii)." J Med Toxicol, 2018. doi:10.1007/s13181-017-0649-x
10. Srikugan L, Sankaralingam A, McGowan B. "First case report of testosterone assay-interference in a female taking maca (Lepidium meyenii)." BMJ Case Rep, 2011. doi:10.1136/bcr.01.2011.3781
11. Memorial Sloan Kettering Cancer Center. "Maca." About Herbs, last updated 7 June 2023. mskcc.org.
12. GOV.UK. "Great Britain nutrition and health claims (NHC) register." Updated 19 May 2026. gov.uk.
13. NHS. "Vitamin D." Page last reviewed 03 August 2020, checked 1 November 2026. nhs.uk.
14. NHS. "Who can and cannot take colecalciferol" and "Taking colecalciferol with other medicines and herbal supplements." Pages last reviewed 10 January 2023. nhs.uk.

Food supplements are not intended to treat, cure or prevent any disease. If you are pregnant, breastfeeding, taking medication, or have a medical condition, consult a healthcare professional before use.