Caving to an energetic pressure campaign, the Drug Enforcement Administration on Wednesday said it will drop a proposed emergency ban on kratom, a Southeast Asian tree leaf product that consumers say treats pain, addiction and a long list of other conditions.

The DEA now will open a public comment period ending Dec. 1, after which it will decide whether or not to move forward with a ban or some other restriction on kratom, which generally is brewed as tea or consumed in pills.

“Based on the response we’ve gotten over the last month or so, we believe it’s the prudent and reasonable action to take,” DEA spokesman Russ Baer says. “We want to make sure this is a transparent process. We want to have an open dialog with the public.”

It’s a big win for kratom users, who burned up the phone lines of the DEA and Congress, where dozens of lawmakers signed letters asking the anti-drug agency to reconsider.

"Today we are thankful to the DEA for listening to the voices of consumers, congresspeople and research scientists studying this plant," says Susan Ash, who corralled the backlash, including a well-attended White House protest, as leader of the American Kratom Association consumer group.

"We still believe no scheduling is necessary because it’s been used safely here in the U.S. for decades and across the world for millennia," Ash adds. "While we are very thankful that our voices are heard today, we still have a lot of work cut out for us."

The DEA initially surprised and enraged consumers in August with a sudden announcement that it would make two compounds in kratom – mitragynine and 7-hydroxymitragynine – Schedule I substances, effectively banning the plant with as little as 30 days' notice.

More than 2,000 kratom consumers, the vast majority opposed to the ban, proceeded to call the DEA and share their stories.

“They have claimed individually that kratom has given them medical value,” Baer says, “that it has medical utility ranging from migraine headaches to chronic pain, to Crohn's disease, to anxiety, depression, opioid withdrawal – these are all conditions that medicines usually try to alleviate. ”

Though scientists are only beginning to understand its effects, consumers tout kratom as a natural painkiller without the fogginess of pharmaceuticals, as an energy-boosting mood elevator, and as a way to stay away from addictions, particularly to opioids.

But the DEA points to assertions that it can sometimes become addictive and claims 15 deaths in the U.S. are associated with its use. Kratom advocates say many people don’t experience withdrawal after regular use and that they believe most if not all deaths featured other drug use.

Among those who campaigned to keep kratom legal were researchers such as Andrew Kruegel, an associate research scientist at Columbia University. He had to rush to complete a research project before the ban took effect and had to boil in alcohol his stash of kratom to convert the active compounds into non-scheduled analogs ahead of Sept. 30, the initial day the ban could have taken effect.

Initial research shows kratom may offer significant harm-reduction for people who abuse legal painkiller medications or illegal opiates like heroin.

Kreugel told U.S. News research suggests mitragynine and 7-hydroxymitragynine result in different effects than traditionally abused opioids, appearing only to be partial agonists of the mu opioid receptor – with a ceiling effect regardless of dose – and that they also appear to be biased agonists, meaning they activate what is called the G protein pathway but not a separate opioid pathway associated with constipation and respiratory depression, a primary cause of overdose deaths.

"In animal studies, both mitragynine and 7-hydroxymitragynine produce almost no respiratory depression," Kreugel said. "Of course this hasn't been rigorously studied in humans because there have been no clinical trials, but anecdotal evidence – which is quite substantial – suggests that people aren't dying of respiratory depression."

Overdoses involving legal and illegal opioids, including heroin, combined killed more than 28,000 Americans in 2014 alone and many recovering addicts said they were worried what would happen to them if kratom became illegal.

Kruegel said mitragynine and 7-hydroxymitragynine preliminarily appear "similar in terms of pharmacology" to a drug called Oliceridine that is undergoing Food and Drug Administration-approved Phase III trials in humans – something that fuels kratom advocate claims that corporations simply want to ban a natural rival.

Baer says the DEA is awaiting completion of an eight-factor analysis on kratom that it first requested of the FDA in 2014 to underpin a permanent scheduling decision. The DEA's initial emergency scheduling action would have lasted two – or at most three – years.

Baer says there are four options for how kratom regulation will move forward after Dec. 1:

Option One: If the FDA has not completed its analysis, the DEA can issue another notice that it will go ahead with emergency placement in Schedule I, making kratom illegal with as little as 30 days public notice.

Option Two: If the FDA has not completed its analysis, the DEA can wait until it does before taking action.

Option Three: The FDA determines kratom has an accepted medical use, leading to permanent placement in Schedule II, a category of tightly controlled drugs that includes cocaine, or lower – or perhaps no scheduling at all.

Option Four: The FDA determines kratom has no accepted medical use and a high potential for abuse, resulting in a public notice and comment period for proposed permanent listing in Schedule I.

Though it's unclear what ultimately will happen, the ball appears to have been kicked to at least the New Year, and drug policy reform advocates say it's an unprecedented victory.

“This is a truly remarkable moment to see the Drug Enforcement Administration, a law enforcement agency with a long track record of ignoring both science and public opinion, being forced to consider the scientific evidence and public opinion before taking additional steps with respect to kratom,” said Grant Smith, deputy director of national affairs at the Drug Policy Alliance.

But as Ash, the consumer group leader, says, advocates will indeed have battles ahead.