By Dr. Jennifer Stephani, St. Peter Emergency Department, Board-Certified Toxicologist
What is kratom?
Kratom is derived from Mytragena speciosa, a plant native to Southeast Asia. Kratom contains multiple active alkaloids, including mitragynine, which has mixed agonist/antagonist opioid activity with additional serotonergic and adrenergic activity. It has been used for many years brewed into a tea for mild effects. Over years, use has shifted to pulverizing the leaf into powder and adding it to liquid, making its clinical effect more pronounced. It is frequently used by people to self-treat opioid use disorder but is sometimes used recreationally. It is widely available at smoke shops.
What is 7-OH mitragynine?
7-OH has much more potent opioid effects than mitragynine, with a greater binding affinity to the mu opioid receptor. There are trace amounts of 7-OH mitragynine found in kratom, but it represents <2% of leaf material. Because extraction is not reasonable, it is made semisynthetically by chemically altering mitragynine. 7-OH is available as pills, liquids, powders and gummies, and is available in smoke shops and gas stations. The semisynthetic products are sometimes added back into kratom.
7-OH is an agonist at the mu opioid receptor and antagonist at the kappa and delta opioid receptors. In mouse models, there is cross-tolerance to morphine, and 7-OH induces withdrawal signs equal to morphine. It is considered equipotent to oxycodone, with some products containing up to 200 mg of 7-OH. In addition, products are not regulated or monitored, and adulterants such as amphetamines, ephedra and tramadol have been detected in samples.
Acute clinical and adverse effects
Clinically, cases of severe overdose from the original kratom plant are rare due to mild clinical effect. The more potent 7-OH can cause a more severe opioid overdose. Acute overdose typically produces an opioid presentation without severe serotonergic or adrenergic effects and is treated acutely with naloxone.
Adverse effects seen include nausea, vomiting, dry mouth, elevated blood pressure, hallucinations, seizures, and cholestatic liver failure. More recently, acute pulmonary injury, including alveolar hemorrhage and eosinophilic pneumonitis has been described [1].
There is no rapid testing for mitragynine or 7-OH. Reported deaths are difficult to interpret, because 7-OH is unstable in biologic specimens and breaks down before testing can be done.
Withdrawal
Both mitragynine and 7-OH are opioids, producing an opioid withdrawal syndrome with chronic use. Kratom started becoming popular in 2010 and withdrawal syndromes were much more common by 2015. It is treated like other opioid use disorders, most often using buprenorphine. Patients can be referred to local substance use treatment centers for treatment.
Emergency scheduling of kratom
Kratom has been used in US for more than 10 years. Poison center data have showed increased exposure to kratom-based products from less than 200 in 2014 to greater than 1600 in 2024 with more than 40% of 7-OH reports coming from individuals abusing the drug[2]. In 2016, kratom was almost banned, but the DEA walked back the ban at the last minute due to heavy pressure from kratom lobbyists. The product has continued to evolve commercially to include the more dangerous enhanced semisynthetic alkaloids.
On July 1, 2026, the DEA announced the emergency scheduling to temporarily place 7-OH mitragyinine and three related compounds (pseudyindoxyl, MGM-15, and MGM-16) in Schedule 1 of the Controlled Substances Act. This does not include the kratom plant, as long as it contains 7-OH concentrations under the threshold. Availability in smoke shops remains pending broader enforcement. As the restriction progresses, medical providers can expect an increase in opioid withdrawal presentations. These patients can be referred to local substance use programs.
References
1. Kanchustambham V, Saladi S. Kratom-Associated Pulmonary Toxicity: A Systematic Review of Case Reports and Forensic Series with a Proposed Clinical Phenotype Classification. J Med Toxicol. 2026 Aug 27. doi: 10.1007/s13181-026-01153-5. Epub ahead of print. PMID: 42661120.
2. Post, S., Spiller, H. A., Chounthirath, T., & Smith, G. A. (2019). Kratom exposures reported to United States poison control centers: 2011–2017. Clinical Toxicology, 57(10), 847–854. https://doi.org/10.1080/15563650.2019.1569236
