MHRB stands for Mimosa hostilis root bark, the dried root bark of a tropical tree scientifically known as Mimosa tenuiflora. It’s a product that surfaces in discussions about natural dyes, traditional skin remedies, and psychoactive plants. The tree grows natively across a wide stretch of Latin America, from southern Mexico through Central America and into Venezuela and northeastern Brazil.
The Tree Behind the Bark
Mimosa tenuiflora is a scrambling shrub or small tree in the legume family (Fabaceae) that thrives in wet tropical environments. In Mexico, it’s commonly called tepezcohuite. The “hostilis” name comes from an older botanical classification that stuck around in popular usage, so “Mimosa hostilis” and “Mimosa tenuiflora” refer to the same species. The tree is thorny, fast-growing, and well adapted to dry, degraded soils, which is part of why it’s abundant in the Caatinga biome of northeastern Brazil.
The root bark is the part that draws the most interest. It has a dark reddish-purple inner layer that’s visually distinct from the lighter outer bark and woody core. When people refer to MHRB, they almost always mean the inner root bark specifically, since it contains the highest concentrations of the tree’s notable chemical compounds.
What’s in the Root Bark
MHRB contains a complex mix of compounds. The most discussed is N,N-dimethyltryptamine, commonly known as DMT, a powerful psychoactive substance. Concentrations in the root bark typically range from 0.5% to 1.7% by dry weight, with some analyses finding levels as high as 0.9% (roughly 6 to 7 milligrams per gram of bark). Stem bark contains far less, usually around 0.3%, which is why the root bark is the sought-after material.
Beyond DMT, the bark contains a unique compound called yuremamine, first isolated from Mimosa tenuiflora stem bark and classified as a novel type of plant-derived indole alkaloid. Researchers are still working to understand its exact biological role. The bark is also extremely rich in tannins, with a concentration around 16%, which accounts for its deep color and its historical use as a dye and astringent.
Traditional and Folk Uses
In Mexico, tepezcohuite bark has a long reputation as a wound-healing remedy. It has been applied topically to burns, cuts, and skin irritations for generations. After a series of gas explosions in Mexico City in the 1980s, bark preparations gained national attention when they were reportedly used on burn victims. This led to a wave of commercial skincare products marketed with tepezcohuite extract.
In northeastern Brazil, the bark has been used in a traditional drink called jurema or vinho da jurema, which plays a role in certain indigenous and syncretic spiritual practices. DMT on its own is not active when swallowed, because enzymes in the gut break it down before it reaches the bloodstream. Traditional preparations sometimes combine it with other plants containing compounds that block those enzymes, allowing DMT to take effect orally. This is the same basic principle behind ayahuasca, which pairs a DMT-containing plant with a vine that inhibits the same gut enzymes.
Use as a Natural Dye
The high tannin content makes MHRB a popular choice among natural dye enthusiasts. It produces shades ranging from deep purple to warm brown, depending on the fiber and preparation method. To get the color to bond to fabric, you need a mordant: aluminum sulfate works well for wool, while aluminum acetate is better suited for cotton. Adding cream of tartar to the dye bath can shift the hue and soften animal fibers.
MHRB can also modify the color of other natural dyes when used alongside them. Mixed with cochineal or madder, it pushes reds toward brighter, more orange tones. It doesn’t pair well with logwood or certain other tannin-heavy dyes, as it can actually suppress their color development.
What the Clinical Evidence Says About Skin Healing
Despite the strong folk reputation, clinical research on tepezcohuite for skin repair is limited and mixed. One randomized trial tested a hydrogel containing Mimosa tenuiflora bark extract against a plain hydrogel on venous leg ulcers. Both groups saw similar wound-surface reductions (about 6 square centimeters on average), and the bark extract offered no measurable advantage over the hydrogel alone. Lab work and tissue biopsies showed no differences between the two groups either. So while the bark clearly has antiseptic and astringent properties from its tannin content, the evidence for superior wound healing over standard treatments is thin.
Legal Status and Practical Realities
The tree itself and its bark are not universally controlled substances. MHRB is sold online and in specialty shops, often marketed for dyeing or soap-making. However, DMT is a Schedule I controlled substance in the United States and is similarly restricted in most countries. Extracting or concentrating DMT from any source, including MHRB, is illegal in these jurisdictions. The legal gray area exists because the bark in its whole, unprocessed form contains DMT naturally, and enforcement varies by country. In Brazil, Mimosa tenuiflora bark can be legally sold, but producing concentrated DMT from it is prohibited.
People purchasing MHRB should be aware that intent matters legally. Buying bark powder for dyeing fabric is a very different proposition from buying it to extract a controlled substance, and law enforcement in several countries has pursued cases involving large purchases of the bark specifically tied to DMT extraction.
Sustainability Concerns
Mimosa tenuiflora is not currently listed as threatened, and the tree is considered abundant across much of its range. It colonizes disturbed land readily and grows fast, which gives it some natural resilience to harvesting pressure. That said, root bark collection is inherently more destructive than harvesting leaves or even stem bark, since digging up roots can kill or severely damage the tree. Research on medicinal plants in the same northeastern Brazilian dry forests has flagged the need for better management plans for heavily harvested species, including strategies like longer intervals between collections, nursery propagation, and reforestation programs. Whether Mimosa tenuiflora faces real population pressure from commercial demand remains an open question, but the growing global market for MHRB makes it worth watching.