Maca · Weak evidence
What maca is for and what the evidence says
The short answer. Maca is an Andean plant sold as an energiser and a libido aid. The two systematic reviews that exist point in the same awkward direction: there are some favourable trials, but four studies in each case, with small samples and limited methodological quality, and the reviews themselves say no firm conclusions can be drawn. It is not that it has been shown not to work: there is not enough material to say it does. And for sports performance there is nothing at all to support it.
Reviews find no consistent effect. It is listed because it sells, not because it works. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.
01 What it does and how much
Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.
| Effect | How much | Detail |
|---|---|---|
| Sexual function | limited evidence | Four randomised trials. Two suggest a positive effect on sexual dysfunction or desire, one in men with erectile dysfunction as well, and another in healthy cyclists finds nothing. The review concludes that the number and quality of trials do not allow firm conclusions. [1] |
| Menopause symptoms | limited evidence | Four trials, all favourable on the scales used, and the same warning: few studies, small samples and limited methodological quality. The review adds that safety has not been shown either. [2] |
| Sports performance | no evidence | The only trial in athletes within the review, done in healthy cyclists, found no effects. Maca is sold with an energiser look and no body of sports evidence behind it. [1] |
| Hormonal effect | not demonstrated | It is called an adaptogen and credited with balancing hormones. The reviews evaluate symptoms and scales, not an established hormonal mechanism in humans. [2] |
02 How to take it
- Dose. 1.5 to 3 g a day of powdered root is typical on the market; trials use different preparations and doses, which makes them hard to compare.
- When. There is no evidence-backed timing.
- How long before you notice it. The reviewed trials last weeks, usually between six and twelve.
Details that change the result
- There is yellow, red and black maca, and marketing assigns them different functions. The reviews do not split by colour because there are not enough trials to do so.
- Gelatinised means heat-treated to remove starch and make it easier to digest. It is a matter of tolerance, not of proven efficacy.
- It is a food in origin, and as such it is eaten in Peru in larger amounts than in a capsule.
- The menopause review explicitly warns that safety has not been established in large trials either. That is not the same as saying it is dangerous, but it is worth knowing.
03 When it makes sense and when it does not
Worth it if
- As a food, in a shake or at breakfast, without expecting a specific effect.
- If you want to try something with weak signals in favour for libido and what has solid evidence is already covered.
Not worth it if
- As an energiser for training: the only trial in athletes in the review found no effect.
- As a treatment for menopause symptoms or sexual dysfunction, which are conditions with a medical approach.
- Expecting a hormonal effect, which is not established in humans.
04 Sources
Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.
- Shin BC, Lee MS, Yang EJ, Lim HS, Ernst E. Maca (L. meyenii) for improving sexual function: a systematic review. BMC Complement Altern Med. 2010;10:44. Cuatro ensayos aleatorizados: dos favorables en disfuncion o deseo sexual, uno favorable en disfuncion erectil y uno sin efecto en ciclistas sanos; el numero de ensayos, el tamano muestral y la calidad metodologica son demasiado limitados para conclusiones firmes. doi:10.1186/1472-6882-10-44
- Lee MS, Shin BC, Yang EJ, Lim HJ, Ernst E. Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review. Maturitas. 2011;70(3):227-233. Cuatro ensayos aleatorizados con efectos favorables por el indice de Kupperman y la escala climaterica de Greene, pero con muy pocos ensayos, muestras pequenas y calidad limitada; la seguridad tampoco esta demostrada. doi:10.1016/j.maturitas.2011.07.017
This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.
Questions about maca
Answered with the data on this page
- Does maca give you energy?
- There is no sports evidence supporting it: the trial in cyclists included in the review found no effects. It contains no stimulants either. The feeling of energy people describe has not been measured in controlled trials.
- Does maca raise testosterone?
- The systematic reviews evaluate symptoms and sexual function scales, not a demonstrated hormonal increase. Crediting it with an effect on testosterone is getting ahead of the data.
- What is the difference between yellow, red and black maca?
- Marketing gives them different functions, but there are not enough trials to compare colours. The reviews do not split by variety because the available material does not allow it.
- What is gelatinised maca?
- Maca heat-treated to remove part of the starch and make it easier to digest. It changes digestive tolerance, not the evidence of efficacy.
And now, which to buy
Prices, kept apart from the evidence
This page explains what maca does and deliberately names no brand. The comparison is the other half: 33 products from 5 stores from €0.050 per capsule, sorted by price and by how verifiable their certification is.
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