MONTGOMERY, Ala. — A little-known plant-based substance often sold as an herbal supplement to address chronic pain is raising alarm bells in states concerned that it could be as addictive as heroin.

The controversy around kratom — a plant originating in Southeast Asia — has led Alabama to become the sixth U.S. state to ban it. Kratom is now a Schedule 1 drug in Alabama, the same classification as heroin and ecstasy.

The product pictured is one of many the FDA has pulled off the market because of '"undeclared drug ingredients." But researchers say that their work with kratom could eventually lead to the development of nonaddictive alternatives to powerful opiate painkillers. FDA image

Wisconsin, Vermont, Tennessee, Indiana and Arkansas have also banned the botanical supplement, and more states are considering the same course. The federal government, too, has worries about kratom.

The Drug Enforcement Administration designates kratom as a “drug of concern” — meaning that, although it is still technically legal, it poses risks if abused. The U.S. Food and Drug Administration lists kratom as an herbal supplement, which means it is not regulated as vigorously as pharmaceuticals before it reaches consumers. The FDA warns of a range of side effects from vomiting to aggression and hallucinations.

Yet the drug’s popularity is indisputable, and its advocates staunchly insist kratom is nothing more than a natural analgesic that can be safely used to alleviate pain, combat fatigue and reduce depression and anxiety.

“Naturally occurring Kratom is a safe herbal supplement that’s more akin to tea and coffee than any other substances,” the American Kratom Association says on its website.

Kelly Devine, an Alabama native who founded the group Kratom United, says some of the kratom products sold may be mixed with unhealthy additives but the plant itself is a natural pain reliever.

“We’re not seeking drugs, we’re seeking relief,” Devine said.

Kratom grows naturally in Thailand, Malaysia, and elsewhere in Southeast Asia and was traditionally chewed or boiled into tea by workers in that region of the world to boost productivity because kratom at low doses can act like a stimulant.

At higher doses, kratom yields a sedative and pain relief effect. Experts say two properties in the plant — mitragynine and hydromitragynine — bind to the same brain receptors as classic opioids like hydrocodone, though kratom is less potent.

Oliver Grundmann, clinical associate professor of medicinal chemistry at the University of Florida School of Pharmacy, said opioid addicts could get relief from kratom, since the same brain receptors are affected. In a 2013 University of Mississippi study, researchers found that mitragynine “blocked all withdrawal symptoms” in methadone-addicted mice who were fed kratom leaves.

Researchers have seen heroin users cycle to kratom, but Grundmann says addicts are known to begin reusing heroin as the body develops a tolerance to kratom.

Shortly after the law making kratom sales and possession illegal in Alabama took effect May 10, products like brightly colored “Krazy Kratom” bottles were being pulled from the shelves of retailers — gas stations and head shops in particular.

Barry Matson, chairman of the Alabama Drug Abuse Task Force, doesn’t want to stand in the way of anybody getting medication that helps them but doesn’t think solutions can be found in a gas station product.

“We don’t need this on shelves if it’s powerful enough to replace (heroin) for some people.”

Though Matson said there are cases in Alabama of deaths and injuries involving kratom, Grundmann says he’s seen no evidence to indicate kratom was the “sole contributing drug” to an overdose death in the U.S. However, research is so limited that experts aren’t sure how other compounds in the plant interact with other substances.

“We’re always trying to catch up behind the latest trends,” Grundmann said. “There are so many different drugs, so many different ways to abuse drugs that we don’t initially think about.”