The move is "shocking," according to John Hudak, who studies drug policy at the Brookings Institution. "The DEA is not one to second-guess itself, no matter what the facts are."
The DEA had announced in August that it planned to place kratom in schedule 1 of the Controlled Substances Act, the most restrictive regulatory category, as soon as Sept. 30. But since announcing their intent to ban kratom, the "DEA has received numerous comments from members of the public challenging the scheduling action," acting administrator Chuck Rosenberg wrote in the notice, "and requesting that the agency consider those comments and accompanying information before taking further action."
A spokesman for the Drug Enforcement Administration did not immediately respond to requests for comment.
People who take it have have said kratom helped them overcome addiction to opiates or alcohol and treat otherwise intractable pain. Researchers say that their work with kratom could eventually lead to the development of nonaddictive alternatives to powerful opiate painkillers. Placing kratom in schedule 1 would cripple researchers ability to study the drug, they say.
U.S. lawmakers were among the groups expressing their displeasure with the DEA's intent to ban kratom. A group of 51 U.S. representatives wrote to the DEA saying that the DEA's move "threatens the transparency of the scheduling process and its responsiveness to the input of both citizens and the scientific community."
Another group of nine senators said the DEA's "use of this emergency authority for a natural substance is unprecedented," and urged the administration to reconsider.
The DEA will now open up a period for public comment until Dec. 1 of this year. It is also asking the FDA to expedite a "scientific and medical evaluation and scheduling recommendation" for the active chemical compounds in kratom.
At the close of the comment period, a number of things could happen. The DEA could decide to permanently place the plant in a schedule of the Controlled Substances Act, which would require an additional period for lawmakers and the public to weigh in. It could also decide to temporarily schedule kratom, which would not require any additional comment.
It could also decide to leave kratom unregulated.
Advocates for kratom use, who say the plant has helped them treat pain and stop taking more powerful and deadly opiate painkillers said they are elated.
"I am in tears," Susan Ash of the American Kratom Association said in an email. "Our voices are being heard, but we still have a long road ahead of us.
Lawmakers who criticized the initial announcement to ban kratom are also pleased. "Concerned citizens across the country have made it clear, they want the DEA to listen to the science when it comes to the potentially life-saving properties of kratom," said Mark Pocan (D.-Wis.) in an email.
Researchers are welcoming the move, but they point out that the future of their work with the plant is an uncertain one.
Kruegel says that the FDA's evaluation of the drug will carry a lot of weight in the DEA's decision. But the kind of rigorous, controlled trials that the FDA typically refers to in situations like this simply don't exist for kratom.
"Unfortunately, in the United States I don't think we have a good regulatory framework for handling this situation or taking perhaps more reasonable middle paths" between banning the drug outright or keeping it unregulated, Kruegel says.
Still, he says, "the FDA is a scientific agency rather than a law enforcement agency, so I am encouraged that they will now be having more serious input on this important policy decision."
Marc Swogger, a clinical psychologist at the University of Rochester Medical Center who has published research on kratom use and earlier called the decision to ban the plant "insane," said in an email that "I'm happy to see this. It is a step in the right direction and a credit to people who have spoken out against scheduling this plant."
He added "now, the government should take into account, not just the minimal available scientific data on kratom, but the broader impact that criminalizing the use of this plant will have on vulnerable citizens."