Americans have increasingly sought out the dietary supplement kratom in recent years to help with drug withdrawal, when seeking relief from pain, anxiety or depression and even to get high.

But on Tuesday, the Food and Drug Administration said it was seriously concerned about kratom, which has been associated with at least 36 deaths and with an escalating number of calls to poison control centers.

The supplement, which carries risks of abuse, addiction and even death, might even exacerbate the opioid crisis, the regulator said.

As a result, the FDA — which has previously warned consumers about the supplement — said it is cracking down on kratom imports, seizing and voluntarily destroying kratom products and working with other parts of the federal government to address its risks.

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“We’ve learned a tragic lesson from the opioid crisis: that we must pay early attention to the potential for new products to cause addiction and we must take strong, decisive measures to intervene,” FDA Commissioner Scott Gottlieb said. “From the outset, the FDA must use its authority to protect the public from addictive substances like kratom, both as part of our commitment to stemming the opioid epidemic and preventing another from taking hold.”

Kratom is an Asian plant that has been available in the U.S. as a pill, a powder, a liquid, a whole leaf and in other forms. Like other dietary supplements, kratom has been mostly unregulated, with observers comparing the market to the Wild West.

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Kratom has encountered regulatory scrutiny before. Last year, the Drug Enforcement Administration said it would classify the drug as a Schedule I substance. But after intense pushback from manufacturers and activists, the DEA said it would instead consider public comments before taking any action.

The supplement is currently a controlled substance in 16 countries and banned in several states, the FDA said.

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Imports of kratom have increased in recent years, according to a FDA import alert late last year, which noted that health problems associated with the product included severe withdrawal symptoms, respiratory depression, hallucinations, aggression and more.

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Kratomk’s use as a way to ease opioid withdrawal is especially “troubling,” the regulator said, since there is “no reliable evidence” to suggest it’s a good treatment for opioid use.

Though it’s possible that the supplement could help, a product would need to go through clinical trials and the appropriate FDA channels, the regulator said.

No company has tried to “properly” develop a kratom-containing drug, according to the FDA, and there are no FDA-approved medical uses of the product.

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This story was first published on November 14.