January 6, 2016 – The American Food and Drug Administration (FDA) just announced that U.S. Marshals, at the agency’s request, seized nearly 90,000 bottles of dietary supplements labeled as containing kratom, which itself contains as component, among others, the compound mitragynine. The product, manufactured for and held by Dordoniz Natural Products LLC, located in South Beloit, Illinois, is marketed under the brand name RelaKzpro and worth more than $400,000.“We have identified kratom as a botanical substance that could pose a risk to public health and have the potential for abuse,” said Melinda Plaisier, the FDA’s associate commissioner for regulatory affairs. “The FDA will continue to exercise our full authority under law to take action on these new dietary ingredients, especially if they ignore the notification requirements, as part of our commitment to protecting the health of the American people.
”Mitragyna speciosa”, commonly known as kratom, is a botanical substance that grows naturally in Thailand, Malaysia, Indonesia and Papua New Guinea. Besides mitragynine, there are more than 40 compounds in M. speciosa leaves, including many alkaloids such as mitraphylline, 7-hydroxymitragynine, and
mitragynine pseudoindoxyl. Other active chemicals in M. speciosa include raubasine (best known from Rauwolfia serpentina) and some yohimbe alkaloids such as corynantheidine. M. speciosa also contains at least one alkaloid (rhynchophylline) that is a calcium channel blocker, and reduces NMDA-induced current. The amount of mitragynine within the leaves depends highly on many factors, one major factor is the location of the tree. When trees are grown in Southeast Asia, the levels tend to be higher but when grown elsewhere (even in greenhouses) the levels tend to be low or non-existent. One analysis of products marketed as kratom leaf found, using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS), mitragynine at levels of 1–6% and 7-hydroxymirtrogynine at levels of 0.01–0.04%. The chemical structure of mitragynines incorporate the nucleus of the tryptamine, and these may be responsible for the molecules observed in the serotonin and adrenergic systems. The pharmacological effects of kratom on humans are not well studied. Its metabolic half-life, protein binding, and elimination characteristics are all unknown. Kratom behaves as a μ-opioid receptor agonist, similar to opiates like morphine, although its effects differ significantly from those of opiates.
The FDA is warning consumers not to use any products labeled as containing kratom. Health care professionals and consumers should report any adverse events related to products containing kratom to the FDA’s MedWatch program by: