Muira puama is an Amazonian tree bark used traditionally as a nerve tonic and sexual enhancer, and modern research suggests it has genuine biological activity in at least two areas: sexual function and brain health. Sometimes called “potency wood,” the bark and root of Ptychopetalum olacoides have been used by indigenous communities in the Amazon for generations, typically brewed as a tea or applied as a poultice. While human clinical data remains limited, animal and laboratory studies point to real mechanisms behind many of its traditional uses.
What’s Actually in Muira Puama
Researchers have isolated 14 distinct compounds from the bark, with two alkaloids, magnoflorine and menisperine, making up roughly 76% of the plant’s measurable active ingredients. This matters because alkaloids are the class of plant chemicals responsible for many potent biological effects (caffeine and morphine are both alkaloids, for context). Beyond those dominant compounds, the bark also contains flavonoids like luteolin, phenolic acids like caffeic acid and ferulic acid, and plant sterols including sitosterol and campesterol.
The sterols are particularly relevant to muira puama’s reputation as a sexual enhancer. These compounds are structurally similar to hormones like testosterone and can interact with the body’s hormone receptors. The bark also contains volatile oils that appear to influence nervous system activity, contributing to its traditional use as a nerve stimulant.
Sexual Function and Libido
Muira puama’s most well-known use is for improving sexual desire and erectile function. The mechanism appears to work on two fronts. First, its plant sterols activate hormone receptors in the body, which can increase libido and sexual responsiveness. Second, research in animal models shows that muira puama increases the expression of nitric oxide synthase, the enzyme responsible for producing nitric oxide in blood vessels. Nitric oxide is the same molecule targeted by common erectile dysfunction medications: it relaxes blood vessel walls and increases blood flow.
A 2015 animal study found that rats treated with a combination of muira puama, ginger, and guarana showed improvements in age-related erectile function and nitric oxide production comparable to results seen with standard erectile dysfunction drugs. The bark also appears to act as a nerve stimulant, heightening physical sensitivity and mental arousal during sexual activity. These combined effects, hormonal activation, improved blood flow, and enhanced nerve signaling, help explain why muira puama has maintained its reputation across centuries of traditional use.
That said, most of this evidence comes from animal studies and traditional reports rather than large controlled trials in humans. The effects are plausible and supported by identified mechanisms, but the strength of the evidence is not yet on par with pharmaceutical treatments.
Memory and Brain Protection
The second major area of research involves muira puama’s effects on the brain, and the findings here are surprisingly specific. A standardized ethanol extract of the bark inhibits acetylcholinesterase, the enzyme that breaks down acetylcholine, a chemical messenger critical for memory and learning. This is the same mechanism used by several Alzheimer’s medications.
What makes the research compelling is that the active compounds cross the blood-brain barrier after oral consumption, something many plant chemicals fail to do. Once in the brain, the extract reduced acetylcholinesterase activity by about 33% in one key memory region of the hippocampus, 20% in another, and 17% in the striatum. In the hippocampus and frontal cortex, specific forms of the enzyme were inhibited by 50 to 72%. These are meaningful reductions in the areas most associated with forming and retrieving memories.
In mouse models of Alzheimer’s disease, the extract reduced the harmful effects of amyloid-beta plaques, the protein clumps associated with the disease. Earlier studies from the same research group had already shown that muira puama acts as an antioxidant in the brain and helps hippocampal cells survive oxygen deprivation. Elderly communities in the Amazon have long favored this plant for cognitive support, and the laboratory evidence now offers a plausible explanation for why.
Typical Preparations and Dosing
Traditionally, the bark and roots are boiled in water and drunk as a tea, or sometimes applied externally as a wash. In supplement form, muira puama is available as capsules, tinctures, and powdered bark. Doses in the range of 500 to 1,050 mg daily have been described as possibly safe for up to one month, though there isn’t enough clinical data to establish a well-defined dosing range. Most commercial supplements fall within this window.
If you’re choosing a supplement, look for products made from the bark rather than the leaves, since the alkaloids that drive most of the biological activity are concentrated in the bark. Standardized extracts, particularly ethanol-based extractions, are what researchers have used in the studies showing brain and sexual health benefits.
Safety and What We Don’t Know
Muira puama has a relatively clean safety profile based on what’s currently available, but that partly reflects how little formal study it has received. No significant adverse effects have been reported in humans at typical supplement doses. In preclinical (animal) studies, some researchers noted impairment of short and long-term memory at certain doses and reduced physical activity, which is worth noting given that lower doses appear to enhance memory. As with many herbal compounds, dose matters.
There are no well-documented drug interactions, but this is a gap in the research rather than confirmation of safety. Because muira puama influences hormone receptors and nitric oxide pathways, people taking hormone therapies or blood pressure medications should be cautious. The effects on nitric oxide production also mean it could theoretically interact with erectile dysfunction drugs, amplifying their blood-pressure-lowering effects.
The biggest limitation is the lack of large, controlled human trials. Most of the promising findings come from animal models and laboratory experiments. The traditional use spanning centuries provides a degree of confidence in basic safety, but it can’t substitute for clinical evidence on long-term use or precise effective dosing.