Scientists Identify the Lethal Dose of Kratom’s Active Ingredients

For thousands of people, the opioid-like plant kratom has been life-changing. But like many drugs, it’s not without potential risks. While patient interviews have revealed that kratom can offer some patients with chronic health conditions the relief that conventional opioids hadn’t and in some cases curbed dangerous opioid use, the reality isn’t always so neat and clean.

New research indicates that high enough doses of the two active molecules in kratom can cause death in mice, suggesting that it is possible to fatally overdose on the substance.

In a paper published October 31 in the journal Chemical Research in Toxicology, a team of researchers tested mitragynine and 7-hydroxymitragynine, the two main active molecules in kratom, on mice to establish their LD50 — a measure of lethal dosage. When researchers injected these chemicals into mice intravenously, they were lethal at around the same dosage as heroin.

This study comes at an inconvenient time for those who advocate for kratom to remain accessible. The US Drug Enforcement Administration is expected to rule on whether to make kratom illegal, though the timeframe for that decision is extremely unclear. On Friday, a DEA official told Inverse: “It could be next week, it could be the week after that, it could be the next month, it could be sometime next year.” Whatever the case may be, this research does not cast the plant in a flattering light.

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