The Food and Drug Administration calls kratom a dangerous opioid with no medical use, but advocates say it's a life-saving supplement.
What's missing from the debate over whether kratom is miracle or menace, however, is hard science on how it works.
Frequently ground into a fine powder and taken as pills or tea, kratom is a psychoactive drug derived from the leaves of an Asian plant in the coffee family called Mitragyna speciosa. Kratom advocates swear by the stuff, saying it's helped them kick devastating addictions to opioid painkillers.
But the federal regulatory bodies like the FDA and the Drug Enforcement Administration have cracked down on kratom and even tried to ban it. In February, FDA commissioner Scott Gottlieb said "there is no evidence to indicate that kratom is safe or effective for any medical use."
A growing cluster of physicians and researchers are beginning to question the idea that kratom is useless or universally harmful, however. Some say they understand why people looking to get off opioids might find the drug helpful; others say new research suggests the plant's compounds could have untapped potential.
"We're at the precipice of something promising here," Scott Hemby, a professor of pharmaceutical science at High Point University in North Carolina, told Business Insider.
Hemby is the author of a new study on kratom published in the journal Addiction Biology, and his results suggest that the chief compound in the plant could offer therapeutic benefits.
'The yin and yang of kratom'
The kratom plant contains multiple drug compounds, but two main ingredients seem to have the largest psychoactive effects: mitragynine (MG) and 7-hydroxymitragynine (7-HMG). (This is somewhat similar to the way marijuana plants have THC and CBD.)
Mitragynine, or MG, is thought to be the compound with the most therapeutic potential. It is also present in kratom in much higher concentrations than HMG. MG makes up roughly 60% of this type of compound in the plant, while HMG only makes up about 2%.
Hemby's study is the first to use rats to investigate how each of these two compounds affects the brain.
He and his colleagues gave the animals the chance to self-administer each component of kratom by pushing a dial — first HMG, and then MG. They found that the rats quickly took advantage of the opportunity to give themselves the compound HMG, but they were completely uninterested in MG.
"We stood on our heads to get them to self-administer," Hemby said, adding that his team tried upping the doses of MG several times. "It just wasn't working. It was almost like it was innocuous."
In other words, while one of kratom's main compounds appeared to be addictive, the other wasn't at all — in fact, it appeared to have the opposite effect.
That could be promising for people who are turning to kratom for relief from opioid addiction. The drug is known to tap into some of the same brain receptors as opioids — which spurred the FDA to officially call it an opioid in February. But some people believe those characteristics mean kratom could help treat opioid addiction by staunching cravings and reducing withdrawal and relapse.
Hemby's findings also suggest there might be a way to process kratom to capitalize on this therapeutic potential by heightening the effects of one compound while minimizing the effects of the other. Strains of the plant, for example, can be bred to have differing concentrations of MG and HMG.
"It's kind of the yin and yang of kratom," Hemby said.
The results of the study are still preliminary, since the observations were in rats and not people. But this kind of research is considered the gold standard for drug studies at this early phase.
"This is just the very first step," Hemby said.
'I can see how someone who's suffering could derive meaningful benefit from something like this'
Thousands of people say kratom has helped them bounce back from devastating addictions to painkillers. Some individuals have reported that they turned to the formula after trying and failing to get science-backed yet stigmatized treatments like buprenorphine and naltrexone.
Bryce Avey, a 26-year-old California native, told Business Insider that he took kratom daily as a tea to help kick the opioids he became addicted to after wrist surgery.
"It's like a cruel joke that I finally found something that works and the FDA and DEA want it banned," Avey said.
Opioids claimed roughly 42,000 lives in the US in 2016, and 40% of all opioid-overdose deaths involved prescription painkillers like Oxycontin and Vicodin, according to the Centers for Disease Control and Prevention.
One of the most painful parts of addiction to opioids is the set of flu-like symptoms they induce in some people who stop taking them. Patients who've experienced these symptoms, collectively known as withdrawal, say the experience is hellish. There's shakiness, dizziness, headaches, mood swings, and constant diarrhea — not to mention powerful cravings for opioids.
To calm those feelings, people who've run out of their prescriptions often turn to illegal sources of the drug, like painkillers sold on the street or even heroin.
Avey said this is what happened to him. After his surgery, he took his painkillers for a few months until his prescription ran out. Then, he said, "I started buying them illegally."
That turned into a fast downward spiral.
"I quit going to school and working and almost became homeless," Avey said.
When he heard about kratom from a friend, he tried it and found that it eased his symptoms.
Some physicians and pharmaceutical scientists like Hemby say they aren't surprised by those kinds of stories, since kratom acts on some of the same brain receptors as opioids.
"It makes sense that this product would mitigate the symptoms of opioid withdrawal or allow someone to transition from a higher dose to lower dose, or help get off them off of opioids altogether," David Juurlink, a professor of medicine at the University of Toronto, told Business Insider.
That seems to be what happened for Avey, who said he now drinks a cup of kratom tea every morning, has enrolled at a nearby community college, and is working again.
"It had enough of an effect to stop the craving for opiates but not strong enough to prevent me from living my life," Avey said.
Hemby said his study of rats could be a step toward a better understanding this effect.
"People are saying anecdotally that this is helping them get off of opiates and if we look at rats, this may have some connection with what's being reported in humans," he said.
The problem with an unregulated supplement
Currently, there's little to no quality oversight of kratom, which means people like Avey can't verify what pills labeled "kratom" actually contain.
FDA commissioner Gottlieb has said this lack of oversight is what allowed bacterial contaminants like salmonella to slip into kratom batches. An outbreak sickened more than 130 people across the US earlier this year.
In April, FDA intensified its crackdown on kratom, ordering its first mandatory recall of contaminated kratom products made by a company called Triangle Pharmanatural. This summer, the agency went after three more kratom manufacturers that Gottlieb said were engaged in "health fraud scams" that "pose serious health risks." One of those companies went so far as to claim its pills helped fight cancer — an assertion with zero scientific backing.
These examples make Juurlink wary, since any potential benefit kratom offers has to be weighed against risks due to the way the drug is processed and sold.
"Personally, I would never take this stuff," Juurlink said. "When you go to a pharmacy, you know there's quality control, you know precisely how much you're getting, and you know exactly what you're getting. With this, it's impossible to know."
That's why Hemby's new research could be so significant.
"This idea that there may be evidence of kratom's therapeutic potential — to me, that should be enough for the government to say, 'Hey let's look at that more,'" Hemby said.