Kratom sits in gas stations and smoke shops labeled as a botanical supplement, and many people start using it for exactly the reasons the label suggests: energy, pain, mood, or as a way off prescription opioids. Then they try to stop, and what they feel is aching muscles, a running nose, sweats, insomnia, and craving. That is not a coincidence. Kratom works on the same brain receptors as morphine, and understanding that explains both the withdrawal and why researchers are paying attention.
Is kratom an opioid?
Botanically, no: kratom is a tree, Mitragyna speciosa, related to coffee, and its leaves have been chewed or brewed in Southeast Asia for centuries. Pharmacologically, the honest answer is that its main active compounds act like opioids. Mitragynine, the most abundant of kratom's more than 50 alkaloids, is a partial agonist at the mu opioid receptor, the same receptor that morphine, oxycodone, and fentanyl act on. Its metabolite, 7-hydroxymitragynine, usually called 7-OH, is even more potent at that receptor than morphine. Mitragynine also touches serotonin, dopamine, and adrenaline systems, which is why low amounts feel stimulating and larger amounts feel sedating and opioid like.
The FDA's position is direct: kratom's compounds bind the same receptors as opioid drugs and can produce sedation, constipation, physical dependence and withdrawal, and respiratory depression. No prescription or over the counter product containing kratom or its alkaloids is approved for any use in the US. Between 1.6 and 2.1 million Americans aged 12 and older used kratom in the past year across 2019 to 2023, and lifetime use rose from 4 to 5.1 million. Calls to poison centers about kratom rose from 258 in 2015 to 1,524 in 2024. Most of those exposures involved another substance too, which is part of why kratom's risks have been hard to pin down.
Why kratom withdrawal feels like opioid withdrawal
When any opioid receptor agonist is used daily, the brain adapts: it dials down its own signaling to compensate. Stop the drug, and the system is left underactive, which produces the mirror image of an opioid's effects. Opioids calm, slow the gut, dry secretions, and blunt pain. Withdrawal brings anxiety and restlessness, diarrhea and stomach cramps, running nose and watery eyes, yawning, sweating, and aching muscles and joints. Kratom withdrawal produces the same list because it is the same receptor adapting.
The difference is usually degree. Regular kratom users in a 2020 Johns Hopkins survey of nearly 2,800 people mostly described withdrawal as mild to moderate, and about 1 in 8 met criteria for a use disorder. Clinicians who treat kratom withdrawal describe it as resembling withdrawal from a moderate dose of a prescription opioid rather than from heroin or fentanyl. Two things push it toward the severe end: high daily amounts, and concentrated products. Kratom leaf contains less than 2 percent 7-OH by alkaloid content, but the US market now sells extracts and tablets with enriched or synthesized 7-OH, chemically closer to a strong opioid than to a tea. People who use those products report withdrawal that looks much more like classic opioid withdrawal, and in 2025 the FDA moved to restrict 7-OH products, describing them as a public health threat hiding in plain sight.
The kratom withdrawal timeline
Kratom's compounds clear the body over about a day, and the timeline follows from that. It varies with how much and how long a person used, and with the product.
Hours 12 to 24. The first signs appear: anxiety, restlessness, yawning, watery eyes, running nose, and craving. Sleep is often poor the first night.
Days 2 to 3: the peak. Muscle and joint aches, sweating and chills, stomach cramps, diarrhea, nausea, tremor, and strong craving. Irritability and low mood are common. This is the window when most people return to use, and when medical support matters most for people who used heavily.
Days 4 to 7. Physical symptoms ease steadily. Sleep starts to return, appetite comes back, aches fade. Craving persists but comes in waves rather than constantly.
Weeks 2 to 4 and beyond. Physical withdrawal is generally over, but low mood, anxiety, poor sleep, and craving can linger for weeks, sometimes longer, a pattern also seen after opioid withdrawal. For people who used kratom to manage pain or mood, the original problem returns and needs its own plan.
None of this is usually medically dangerous on its own, unlike alcohol or benzodiazepine withdrawal. It is, however, miserable enough that many people cannot get through it unsupported, especially if they used concentrated products. That is the gap treatment and research are trying to fill.
What treatment exists, and why it comes from opioid medicine
There is no treatment approved specifically for kratom withdrawal or kratom use disorder, because kratom was never a prescription drug and the research is young. In practice, clinicians borrow from opioid use disorder. Published case reports describe people whose kratom dependence was treated successfully with buprenorphine, the partial opioid agonist used for opioid use disorder, which makes pharmacological sense: it occupies the same receptor and can be tapered under supervision. Supportive medicines for specific symptoms, such as sleep and stomach cramps, are also used. Behavioral therapy addresses the reasons a person started, which for kratom are often pain, anxiety, or a prior opioid problem.
What is missing is evidence. Almost everything above rests on case reports and surveys, not controlled trials. Nobody has yet run a randomized study of buprenorphine or any other medicine for kratom dependence, no one knows how common lasting dependence is among the millions who use it, and the effects of 7-OH products are studied mostly in animals. This is unusually early stage territory, which means the studies happening now will define what treatment looks like.
What researchers are studying
Kratom research in the US is largely funded by the National Institute on Drug Abuse and concentrated at a few academic centers. The questions are basic and important: what kratom's compounds actually do in the human body at real world amounts, how the body processes them, how dependence develops, and which people are at risk. Johns Hopkins has run the largest human studies, including the first controlled dosing study of kratom leaf and the survey work that produced the 1 in 10 use disorder figure. Because kratom is legal in most states and sold without standardization, one product can contain several times the mitragynine of another, and a large part of current research is simply measuring what is in the products people actually take.
These studies enroll people who already use kratom regularly and are not asked to stop; they measure effects, blood levels, and experiences. That is a different kind of participation than a treatment trial, and for many people it is the first time anyone has asked them, systematically, what kratom does to them.
Two studies recruiting now
A direct observation study of kratom effects in regular consumers measures how kratom products people already use affect them and how the body processes the compounds, one of the few human studies of real world kratom use. A study of a widely sold kratom and kava based drink measures its effects on stress responses and how its ingredients are absorbed, in healthy adults. Neither is a treatment trial; both help fill the evidence gap described above. Because no dedicated kratom treatment studies exist yet, people whose kratom use has become a problem are increasingly included in research on opioid use disorder, where buprenorphine and other approaches are being tested. Our opioid use disorder treatment guide covers those options. Joining any study is voluntary and does not replace your own doctor.
Common questions
Is kratom addictive? It can be. Kratom's compounds act on opioid receptors, and regular daily use produces tolerance, dependence, and withdrawal. In the largest survey of US users, about 1 in 8 met criteria for a use disorder. Risk is higher with daily use, larger amounts, and concentrated 7-OH products.
Is kratom safe? It is not approved as safe for any use, and its products are unregulated, so the amount of active compound varies widely between brands and batches. Poison center calls have risen about sixfold since 2015. Occasional use of leaf products carries lower risk than daily use of extracts, but nobody can currently say what a safe amount is, because the human research to establish that is only now being done.
What is 7-OH kratom? 7-hydroxymitragynine is a minor alkaloid in kratom leaf, less than 2 percent of the total, but far more potent at the opioid receptor than morphine. Products sold as "7-OH" are enriched or synthesized concentrates, chemically closer to a strong opioid than to traditional kratom. They carry higher risks of dependence, withdrawal, and overdose, and the FDA acted to restrict them in 2025.
What helps with kratom withdrawal? Medical support. Clinicians treat it much like opioid withdrawal, with medicines for specific symptoms and, in some cases, a supervised buprenorphine taper, along with treatment for whatever kratom was being used for. Stopping abruptly is not dangerous for most people but is often too uncomfortable to sustain without help. Talking to a doctor or an addiction medicine clinic is the practical first step, and research studies are another way in.