The supplement, which was manufactured by Dordoniz Natural Products LLC, in South Beloit, Illinois, and marketed under the brand name RelaKzpro, is said to be worth upwards of $400,000.
Kratom is made from the leaves of the Mitragyna speciosa plant, and has been widely used for recreational purposes in Southeast Asia, but has recently become popular in the west for its medicinal uses, which include pain relief. It's known for its narcotic effects, but it acts as a stimulant at low doses.
The drug is sold in bars and stores in Florida and other states, where some people are reportedly using it to wean themselves off their heroin addiction. But the drug may be addictive itself and could lead to relapse with heroin, which is cheaper and more potent, The New York Times reports.
How kratom affects the brain
Like heroin, kratom is an opioid, a type of drug that works on the brain's pain-relieving system. When the drug binds to opioid receptors in the brain, it sets off a domino effect of reactions that ramp up pleasurable feelings, leading to what users describe as a high.
The problem is, it can create a dependency that leads to addiction, when people continue to use it despite its harmful effects, which may include lowered breathing rate, vomiting, nervousness, weight loss and constipation.
The FDA, the agency responsible for ensuring drug safety, doesn't regulate kratom as a drug because it is classified as a dietary supplement.
But in 2014, the agency banned imports of kratom because of its potential health dangers. Withdrawal from the drug can cause hostility, aggression, muscle and bone aches and jerky movements, according to the FDA.
An 'adulterated' product
Earlier this month, the FDA detained, or removed RelaKzpro from the marketplace, under the amended Federal Food, Drug and Cosmetic Act. This allows a product to be removed for up to 30 days if it has been adulterated or misbranded.
The US Department of Justice filed a complain on behalf of the FDA in the US District Court for the Northern District of Illinois, saying there was not enough evidence that kratom isn't harmful to human health, and is therefore adulterated.
"We have identified kratom as a botanical substance that could pose a risk to public health and have the potential for abuse," Melinda Plaisier, the FDA's associate commissioner for regulatory affairs, said in a statement. "The FDA will continue to exercise our full authority under