Mitragynine is the primary active compound in kratom leaves, and people use it mainly for pain relief, energy, and to manage opioid withdrawal symptoms. It makes up about 1.6% of dried kratom leaf weight on average and accounts for roughly two-thirds of the plant’s total alkaloid content. While it interacts with opioid receptors in the brain, no health agency has approved it as a treatment for any condition, and its safety profile remains a concern.
How People Use Mitragynine
In Southeast Asia, where the kratom tree grows naturally, people have chewed small amounts of its leaves for generations to reduce fatigue and increase work capacity. More recently, people around the world have turned to kratom products for a wider set of purposes: easing chronic pain, relieving anxiety or depression, boosting energy, and attempting to manage opioid withdrawal.
The effects depend heavily on how much you take. At low doses (a few grams of dried leaf), mitragynine acts more like a stimulant, producing alertness and mild euphoria within about 10 minutes, lasting roughly an hour to 90 minutes. At higher doses, typically 10 to 25 grams of dried leaf, the experience shifts toward sedation, calmness, and a dreamlike state that can last up to six hours. Those higher doses often come with initial side effects like sweating, dizziness, and nausea before the sedative phase takes over.
How It Works in the Body
Mitragynine’s effects come primarily from its interaction with mu-opioid receptors, the same receptors targeted by morphine and other opioid painkillers. However, mitragynine is a partial agonist at these receptors, meaning it activates them less fully than traditional opioids do. This partial activation is thought to explain why kratom produces milder effects than prescription opioids at typical doses.
Your body also converts some mitragynine into a metabolite called 7-hydroxymitragynine, which is 5 to 23 times more potent at opioid receptors. Although 7-hydroxymitragynine makes up only about 1% of kratom’s alkaloid content naturally, the amount your liver produces from mitragynine contributes meaningfully to the overall experience. In July 2025, the FDA recommended scheduling concentrated 7-hydroxymitragynine products as controlled substances, while specifically noting it was not targeting natural kratom leaf products.
Mitragynine doesn’t stop at opioid receptors. It also behaves like a weak activator of alpha-2 adrenergic receptors, the same receptors targeted by clonidine, a medication sometimes prescribed for anxiety, high blood pressure, and opioid withdrawal. This may partially explain why kratom users report calming effects beyond what opioid activity alone would produce.
Pain Relief
Pain management is one of the most commonly reported reasons people seek out mitragynine. The logic is straightforward: it activates opioid receptors, so it reduces pain perception through a similar pathway as conventional painkillers. Many people who use kratom for chronic pain describe it as a way to avoid or reduce their use of prescription opioids.
The challenge is that clinical evidence in humans remains thin. Most pain-related data comes from animal studies or self-reported surveys of kratom users, not controlled trials. Because mitragynine is a partial pioid receptor agonist with lower binding affinity than drugs like morphine, its pain-relieving ceiling is likely lower, which could be either an advantage (less overdose risk) or a limitation (insufficient relief for severe pain).
Opioid Withdrawal
Using kratom to ease opioid withdrawal is one of the most discussed applications, and one of the most contested. Because mitragynine partially activates the same receptors that opioids do, it can blunt some withdrawal symptoms like muscle aches, restlessness, and cravings. In Asia, kratom has a long history of informal use for managing opium dependence.
The evidence for this use is mixed. While people do report symptom relief, research suggests that regular kratom use can itself lead to dependence and its own withdrawal syndrome. The Mayo Clinic notes that rather than treating opioid addiction, kratom use “may lead to addiction and withdrawal symptoms.” This doesn’t mean it’s useless for every person in every situation, but it does mean swapping one dependence for another is a real possibility.
How Long It Stays in Your System
Mitragynine reaches peak blood levels about one to one and a half hours after you take it. After that, concentrations drop quickly for the first six hours or so, then taper off much more slowly. The terminal half-life is surprisingly long: around 43 hours after a single dose and potentially 60 or more hours with repeated daily use. This means the compound lingers in your body for days after your last dose, even though the noticeable effects wear off much sooner.
Liver Concerns
Liver injury is one of the more serious reported risks. Data from the U.S. Drug Induced Liver Injury Network identified 11 cases of liver damage attributed to kratom between 2003 and 2019, with eight of those occurring in just the last three years of that window, reflecting rising use. All 11 patients developed jaundice, with symptoms typically appearing about two weeks after starting kratom. While 11 cases may sound small, kratom accounted for roughly 3% of all liver injuries linked to herbal and dietary supplements in that database.
Drug Interactions
Mitragynine significantly interferes with liver enzymes responsible for breaking down many common medications. It strongly inhibits CYP2D6, an enzyme that metabolizes antidepressants, certain heart medications, and cough suppressants like dextromethorphan. It also inactivates CYP3A4, the enzyme responsible for processing the largest number of prescription drugs.
These aren’t just theoretical concerns. Pharmacological modeling estimates that as little as 2 grams of kratom powder could increase blood levels of certain sedatives by roughly sixfold, a potentially dangerous escalation. If you take any prescription medications, the interaction risk with regular kratom use is substantial, particularly with antidepressants, benzodiazepines, blood thinners, or any drug you’ve been told to avoid grapefruit with (grapefruit inhibits the same CYP3A4 enzyme).
Legal Status
Kratom leaf products remain legal at the federal level in the United States, though several states and municipalities have banned them. The FDA has not approved kratom or mitragynine for any medical use. The agency’s 2025 action specifically targets concentrated 7-hydroxymitragynine products, recommending they be scheduled under the Controlled Substances Act. The Drug Enforcement Administration is reviewing that recommendation through a public rulemaking process. In many other countries, including Australia, several EU member states, and Thailand (which recently re-legalized it under regulation), kratom’s status varies widely.