Kratom is the dried leaf of Mitragyna speciosa, a tropical tree in the coffee family (Rubiaceae) native to Southeast Asia. For generations, laborers in Malaysia, Thailand, and Indonesia chewed the fresh leaf or brewed it into tea. In Malaysia the plant has long been known by its original name: ketum. We took that name because it points back to the plant itself — before the marketing, before the capsules, before the US supplement aisle.
Safety & legal note. Kratom is not approved by the FDA for any use, and nothing here is medical advice. This article reports what is documented about the plant and its chemistry. Kratom is banned in some US states, is not for anyone under 21, and can cause dependence with heavy use. Buy only lab-tested product and check your local law.
The plant and its alkaloids
The pharmacology of kratom is driven mainly by two alkaloids that researchers have characterized in detail:
- Mitragynine — the most abundant alkaloid in the leaf, typically making up the majority of total alkaloid content.
- 7-hydroxymitragynine — present in much smaller amounts in the raw leaf, but studied because it is more potent at the receptors involved.
Both compounds interact with the body's opioid receptors, though the research literature describes this interaction as pharmacologically distinct from classic opioids (for example, differences in how the receptors signal downstream). Dozens of other minor alkaloids are present in the leaf, but mitragynine and 7-hydroxymitragynine are the two that vendor Certificates of Analysis (COAs) most often quantify.
"Strains" are mostly a sourcing label
Kratom is sold under strain names like Red Bali, Green Maeng Da, or White Borneo. These names combine a vein color (red, green, white, or yellow) with a region (Bali, Borneo, Maeng Da, Malay, Thai, and so on).
Vein color reflects how mature the leaf was at harvest and how it was dried. Region names are largely marketing and sourcing labels — they are not standardized between vendors, and independent testing has repeatedly found that the alkaloid profile of a given "strain" can vary a lot from batch to batch and seller to seller. That is exactly why lab testing matters more than the name on the bag. Our strain guide reports what community sources commonly associate with each type, while being clear that these are self-reported observations, not clinical findings.
Powder, capsules, extracts, and why testing matters
Kratom is sold as loose powder (crushed leaf), capsules (the same powder, measured), and extracts (concentrated alkaloids, often labeled by a multiplier or a 7-hydroxymitragynine percentage). Extracts are far more concentrated than plain leaf and carry a correspondingly higher risk profile.
Because kratom is an agricultural product sold in a lightly regulated market, contamination is a real and documented problem. The FDA has issued recalls and warnings over salmonella and heavy metals (lead, nickel) in kratom products, and independent testing has found products adulterated with synthetic 7-hydroxymitragynine. The single most protective thing a buyer can do is choose vendors that publish a current, per-batch third-party COA. The American Kratom Association's GMP program audits vendors against manufacturing and testing standards, and we weight it heavily in our vendor rankings.
Where kratom stands legally
Kratom is legal under US federal law, but the picture is a patchwork at the state and local level. A handful of states ban it outright, several have passed Kratom Consumer Protection Acts (KCPAs) that set labeling and age standards, and some cities and counties have their own ordinances. Our state-by-state legality guide reports the current status wherever you are — but it reports the law, it does not give legal advice.
The bottom line
Kratom — ketum — is a botanical with a long traditional history and a genuinely complex, still-evolving research picture. It is not a miracle product and it is not risk-free. If you choose to buy it, buy tested product, know your state's law, and treat concentrated extracts with far more caution than plain leaf.