Indigenous Americas
Maca (Andes/Inca), Muira Puama (Amazon 'Potency Wood') & Plant Sovereignty
Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- Not FDA evaluated; sold as dietary supplements
Reference only. Not medical advice.
What can go wrong
Maca is generally well tolerated in trials, though long-term and high-dose safety data are limited and goitrogen content (as a cruciferous plant) is a theoretical concern. Muira puama lacks rigorous safety data. As supplements, both carry the usual risks of inconsistent potency and adulteration in the men's-health category.
This is something to take to a clinician. The Atlas can tell you what is known about indigenous americas in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Indigenous American traditions contribute two prominent male-health botanicals: Maca (Lepidium meyenii), a cruciferous root cultivated for millennia on the high Andean plateau of Peru and tied to Inca-era use, and Muira puama (Ptychopetalum olacoides), an Amazonian shrub known in Brazilian traditional practice as 'potency wood' (marapuama). Small human trials suggest Maca may improve libido and sexual function independent of testosterone (grade 2); Muira puama evidence is mostly anecdotal and preclinical (grade 2). Both raise an active sovereignty and benefit-sharing concern: commercial exploitation of indigenous plant knowledge often returns little to source communities.
Andean and Amazonian plant knowledge now commercialized worldwide, often without benefit-sharing.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
How it is supposed to work
Maca's mechanism is unclear; notably, controlled studies show libido effects without changes in testosterone or estrogen, suggesting a non-hormonal pathway, possibly via macamides or central effects. Muira puama's putative actives are sterols and lipids; mechanism in humans is unestablished and most data are preclinical or uncontrolled.
What people get wrong
Often saidMaca is a natural testosterone booster
ActuallyControlled trials show libido changes without measurable testosterone increases; its effect, if real, appears non-hormonal.
Often saidThese plants are 'discovered' superfoods
ActuallyThey are long-standing indigenous crops and medicines; framing them as new discoveries erases the cultures and obscures unresolved benefit-sharing obligations.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
Most value capture occurs downstream among foreign supplement brands and processors, not among Andean or Amazonian source communities, the central benefit-sharing grievance.
How we got here
Maca has been cultivated on the Andean altiplano of central Peru for an estimated 1,300-2,000 years, valued by pre-Columbian and Inca-era peoples as a food and fertility aid for humans and livestock at extreme altitude. Muira puama appears in the traditional pharmacopoeia of Amazonian peoples of Brazil as a tonic for sexual and nervous complaints, entering European herbals in the 19th century. From the 1990s onward, both were heavily commercialized abroad. Maca became a flashpoint in biopiracy debates after foreign patents were sought on Maca extracts, prompting Peruvian objections and invoking the access-and-benefit-sharing principles later formalized in the Nagoya Protocol (2010, in force 2014).
- ~1-2nd millennium of cultivationMaca grown on the Andean altiplano
- Pre-Columbian / Inca eraDocumented Maca use for fertility and stamina
- 19th c.Muira puama enters European herbal literature
- 1990s-2000sGlobal commercialization; Maca biopiracy disputes and foreign patent attempts
- 2014Nagoya Protocol on benefit-sharing enters into force
The people taking it
Maca is now a global supplement and 'superfood,' marketed for energy, fertility, and libido; Peru is the primary producer but faces competition from cultivation in China, raising disputes over germplasm export. Muira puama is a common ingredient in multi-herb men's-vitality blends.
What we do not know
- Is Maca's libido effect reproducible in large, well-controlled trials?
- Do Maca color types differ pharmacologically?
- Will benefit-sharing obligations ever be enforced for these crops?
The market for this
What follows describes how this is bought and sold. It is not a buying guide and it is not an endorsement of any seller.
Peruvian altiplanoSmallholder Maca cultivation and harvestBrazilian AmazonMuira puama wild-collectedChinaCompeting Maca production from exported germplasmGlobal brandsFinished extracts and blends
At a glance
- Maca
- Lepidium meyenii, Andean Peru, 3,800-4,500 m elevation
- Muira puama
- Ptychopetalum olacoides, Brazilian Amazon
- Maca color types
- Yellow, red, and black, with possibly differing effects
- Issue
- Biopiracy / benefit-sharing under the Nagoya Protocol
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Indigenous Americas. A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Maca RCT (Gonzales et al.)2002
Maca improved self-reported sexual desire in men without changing serum testosterone or estradiol
Maca systematic review (Shin et al.)2010
Found limited evidence suggesting Maca may improve sexual function, but called for larger trials