Americans' use of kratom, a plant-based drug often promoted as an alternative to opioids that has been banned in several states, is rare overall but more common among those who use other drugs, according to research published Thursday.

Kratom acts on some of the same receptors as opioids, producing effects including stimulation and pain relief, depending on dosage. While the substance is legal on a federal level, it has not been approved by the Food and Drug Administration for any particular use. 

Despite the lack of government endorsement, 0.7% of American adults and adolescents have used kratom in the past year, according to the American Journal of Preventive Medicine paper, one of the first to examine the drug on a nationwide scale. 

"A lot of smaller, local studies of kratom use have been done, but we've been lacking a larger, national focus," sole author Joseph J. Palamar, a professor at New York University's Grossman School of Medicine, told The Academic Times. 

Use of kratom, which is commonly sold in pill, capsule, extract and tea forms, is disproportionately prevalent among people with depression and serious mental illness, as well as men, white people and younger people, Palamar found. 

While 0.9% of men reported using the substance, just 0.6% of women said the same. Among 18- to 34-year-olds, 1.4% of respondents had used kratom in the last year, compared to 0.8% of 35- to 49-year-olds and just 0.3% of both 50-plus and 12- to 17-year-old respondents. 

Broken down by race, 0.9% of white people had used kratom in the last year, compared to 0.2% of Black people, 0.4% of Hispanics and 0.5% of people the study classified as "other/mixed." 

These demographic traits mirror those of opioid users, who are more white and male than Americans overall. 

Despite lacking FDA approval, kratom is commonly billed as an alternative for people who are seeking to manage pain and avoid withdrawal from opioids. According to a 2020 International Journal of Drug Policy paper, 47% of internet kratom vendors claim the drug relieves pain and 25% said it helps with opioid withdrawal, statements that are not backed up by the Food and Drug Administration. 

Indeed, Palamar's study showed that kratom was far more popular among opioid users than the general population. Among heroin addicts, 16% had used kratom in the last year. For people addicted to prescription opioids, that number was 10.4%. 

Kratom consumption was also somewhat more common among users of marijuana, cocaine, tranquilizers, prescription stimulants and methamphetamine. 

"I wasn't surprised that people with opioid use disorder were more likely to use, but I wasn't necessarily expecting marijuana use disorder to be a correlate," said Palamar, who has also studied how the coronavirus pandemic changed drug trafficking. 

Palamar's paper used data from the U.S. Department of Health and Human Services' 2019 National Survey of Drug Use and Health, a "nationally representative" sample of 56,136 people. Notably, the survey did not represent the more than 2 million people who are incarcerated in the U.S. 

Alabama, Arkansas, Indiana, Tennessee, Vermont, Wisconsin and Washington, D.C., had banned kratom as of March 2020, according to the Associated Press. Illinois and Louisiana ban the sale of kratom to minors, and other states, including Mississippi, have considered bans. Federally, the Drug Enforcement Agency considers kratom a "drug of concern." 

Yet kratom appears to be relatively safe, at least in comparison to drugs like alcohol, cocaine and heroin, which are each involved in thousands of deaths each year. By comparison, a Centers for Disease Control and Prevention analysis found that kratom was listed as a cause of death in 152 out of 27,338 overdose deaths in the U.S. from July 2016 to December 2017. Out of the overdose deaths where kratom was present, 65% also involved fentanyl, 33% involved heroin, 22% involved benzodiazepines and 20% involved prescription opioids. 

"Opioid-involved deaths often involve other drugs, too. It can be hard to weed out what drug or drugs — or effects of combinations of drugs — lead to adverse effects including death," Palamar said. "Kratom doesn't seem like the most dangerous substance, but of course more research is needed."

Kratom's potential to help with opioid withdrawal needs more research, according to Palamar. 

"Well-designed trials are needed to determine kratom's efficacy of reducing opioid withdrawal and/or getting people off opioids," he said. 

The paper, "Past-year kratom use in the U.S.: Estimates from a nationally representative sample," published April 29 in the American Journal of Preventive Medicine, was authored by Joseph J. Palmar, New York University.