The U.S. Food and Drug Administration has issued a strong warning to consumers to stay away from the herbal supplement kratom, saying regulators are aware of 36 deaths linked to products containing the substance.

Laurie McGinley of The Washington Post writes consumers are increasingly using the supplement, which comes from a plant in Southeast Asia, for pain, anxiety and depression, as well as symptoms of opioid withdrawal. The herb also is used recreationally because it produces symptoms such as euphoria. Proponents say it is a safe way to deal with chronic pain and other ailments, and some researchers are exploring its therapeutic potential, including helping people overcome addictions.

But in a statement, FDA Commissioner Scott Gottlieb said that there is no “reliable evidence” to support the use of kratom as a treatment for opioid-use disorder, and that there are no other FDA-approved uses for kratom.

Rather, he said, evidence shows that the herb has similar effects to narcotics like opioids, “and carries similar risks of abuse, addiction and, in some cases, death.” He said that calls to U.S. poison control centers involving kratom increased tenfold between 2010 and 2015, and that the herb is associated with side effects including seizures, liver damage and withdrawal symptoms.