FDA sends warning letters to companies selling synthetic form of compound found in kratom

According to a press release published by the U.S. Food and Drug Administration (FDA) today, the agency has sent seven warning letters to companies illegally marketing products containing 7-hydroxymitragynine (7-OH), a chemical compound found in kratom. The compound is found in negligible amounts in kratom but is often synthesized and added to products at dangerously high concentrations. Not recognized as a dietary supplement ingredient, 7-OH is unlawful to market in supplement products or conventional foods.

The American Kratom Association (AKA; Gainesville, VA) has praised the actions of FDA, having submitted 18 of its own complaints to FDA in May 21, 2025 “reporting vendors selling chemically manipulated 7-OH, pseudoindoxyl, and 'M' products that are identified in the new warning letters that identify illegal therapeutic claims, unlawful product formulations, and deceptive labeling practices that violate federal law and put consumers at significant risk.” Kratom, as an herb, also operates in a regulatory gray area, but sellers of the herb feel that synthetic and adulterated products pose a danger to consumers and reflect negatively on the kratom industry as a whole.

“This FDA action shines a spotlight on a massive and growing problem in the kratom marketplace,” said Mac Haddow, senior fellow on public policy for AKA in a statement. “The companies that received these Warning Letters are just some of a significant number of companies engaged in transparently improper marketing — misleading consumers by branding these 7-OH products as ‘kratom’ while making illegal health claims and using unsafe synthetic or semi-synthetic formulations – and none of these products are kratom. This is a massive fraud on consumers that puts their safety directly at risk.”

The Natural Products Association (NPA; Washington, D.C.) also praised FDA’s actions. “Based on peer-reviewed research from leading experts, highly concentrated or semi-synthetic 7-OH products pose significant public health risks and have been falsely marketed as ‘kratom,’” said Daniel Fabricant, PhD, president and CEO of NPA, in a press release. “These 7-OH products are not legitimate ‘dietary supplements,’ and NPA encourages FDA in collaboration with the U.S. Department of Justice to take any necessary steps to swiftly remove them from U.S. commerce.”