Kratom carries real health risks because its active compounds bind to the same brain receptors as opioids, creating potential for dependence, organ damage, and dangerous interactions with other substances. Despite being sold as a natural supplement, it is not approved by the FDA for any medical use, and the agency actively warns consumers against using it.
How Kratom Acts on the Brain
Kratom’s two main active compounds, mitragynine and 7-hydroxymitragynine, are partial activators of the same receptor that morphine targets. This is the mu-opioid receptor, responsible for pain relief, euphoria, and sedation. The more potent of the two, 7-hydroxymitragynine, has roughly 5 to 23 times more binding strength than mitragynine, though it’s still weaker than morphine overall. Because it hits the same receptor system, kratom produces opioid-like effects: pain reduction, mood elevation, and at higher doses, sedation and slowed breathing.
Kratom also activates receptors involved in adrenaline, serotonin, and dopamine signaling. This broader activity helps explain its stimulant effects at low doses and its wide range of side effects, from elevated heart rate to mood disturbances.
Dependence and Withdrawal
Regular kratom use can lead to physical dependence, meaning your body adapts to the substance and reacts when you stop. Withdrawal symptoms typically appear within 12 to 48 hours of the last dose and generally last one to three days, though some people experience them for up to a week. The symptom profile closely resembles opioid withdrawal: muscle aches, jerky limb movements, nausea, vomiting, abdominal cramping, diarrhea, sweating, hot flashes, and disturbed sleep.
The psychological side can be equally difficult. Restlessness, irritability, depressed mood, anxiety, and intense cravings are commonly reported. The FDA has specifically flagged substance use disorder as a known risk, and cases of neonatal abstinence syndrome have been documented in newborns whose mothers used kratom during pregnancy, with infants showing jitteriness, irritability, and muscle stiffness after birth.
Liver Damage
Chronic kratom use has been linked to acute liver injury, typically appearing within one to eight weeks of regular use. The average time to onset is about 21 days. Early symptoms include fatigue, nausea, itchy skin, and dark urine, followed by jaundice (yellowing of the skin and eyes). The pattern of injury tends to involve bile flow disruption rather than direct cell destruction, though both can occur. At least two dozen cases of clinically apparent liver injury with jaundice have been documented in the medical literature, with a similar number reported to the FDA’s adverse event database.
Heart and Digestive Problems
Kratom has measurable effects on the cardiovascular system. In a study of regular kratom users in Malaysia, the odds of having a resting heart rate above normal were about 8.6 times higher compared to non-users. U.S. poison control data shows that roughly one in five adults exposed to kratom alone reported a rapid heart rate. Cardiovascular effects were even more common in older adults: reported in 37% of kratom-only cases among people in their 60s, and in 52% of those 70 and older. Clinical reports have also documented elevated blood pressure, heart rhythm abnormalities, and in rare cases, cardiac arrest.
Digestive problems are the most frequently reported negative reaction. Nearly 4 out of 5 current kratom users who experienced side effects reported stomach problems. About 5% of surveyed users reported constipation, a predictable effect given that kratom activates opioid receptors in the gut. Nausea, vomiting, and diarrhea also appear regularly in both user surveys and poison control reports.
Seizures and Neurological Effects
Kratom toxicity has been associated with seizures, including full tonic-clonic (grand mal) episodes. Case reports describe individuals who developed seizures after sustained kratom use, and brain imaging research suggests chronic use may cause structural changes visible on MRI. Some chronic users have developed recurrent seizures requiring ongoing treatment with anti-seizure medication. Other neurological complications reported in the literature include psychosis with hallucinations, mania, and a condition called posterior reversible encephalopathy syndrome, which involves swelling in the brain and can be life-threatening.
Overdose Deaths Are Rarely Kratom Alone
CDC data from a 27-state review of overdose deaths between July 2016 and December 2017 found 152 deaths where kratom was detected on postmortem toxicology. A medical examiner determined kratom was a contributing cause in 91 of those cases. Only seven involved kratom as the sole substance detected, and even in those cases the presence of undetected substances couldn’t be ruled out.
The vast majority of kratom-positive deaths involved other drugs. Fentanyl or its analogs were listed as a cause of death in 65% of kratom-positive cases. Heroin appeared in 33%, benzodiazepines in 22%, prescription opioids in 20%, and cocaine in 18%. This doesn’t mean kratom is safe on its own. It means the greatest lethal risk comes from combining kratom with other depressants, particularly synthetic opioids, which can compound its effects on breathing.
Drug Interactions
Kratom interferes with the liver enzymes that metabolize a wide range of common medications. Its strongest effect is on an enzyme called CYP2D6, which processes many antidepressants (including sertraline), beta-blockers, and some pain medications. It also inhibits enzymes involved in breaking down blood thinners and anti-fungal drugs. When kratom slows down these enzymes, other drugs can build up to higher-than-expected levels in your bloodstream, potentially causing toxicity from medications you’re taking at normal doses.
This is particularly concerning because many people who use kratom are self-treating pain, anxiety, or depression, and may also be taking prescription medications for those same conditions.
Contamination in Products
Because kratom is not regulated as a drug or approved dietary supplement in the U.S., products on the market face no standardized quality controls. FDA laboratory testing of 30 kratom products from various vendors found significant levels of lead and nickel in nearly all of them, at concentrations exceeding safe daily exposure limits for oral intake. Some products contained nickel levels above 20,000 parts per billion and lead levels above 1,000 parts per billion. For heavy users, cumulative exposure could lead to nervous system damage, kidney problems, anemia, high blood pressure, or increased cancer risk.
Beyond heavy metals, the FDA has also flagged kratom product recalls due to Salmonella contamination. Without regulatory oversight, there is no reliable way for consumers to verify what is actually in a kratom product, how potent it is, or whether it’s free from contaminants.
Regulatory Status
Kratom occupies a gray area in U.S. law. It is not a controlled substance at the federal level, but the FDA has determined it is not lawfully marketed as a drug, dietary supplement, or food additive. The agency considers kratom-containing supplements to be adulterated products and has partnered with U.S. Customs and Border Protection and the Department of Justice to limit the sale of unlawful kratom products. Several states and municipalities have banned it outright, while others have passed consumer protection laws requiring labeling and purity standards without banning the substance.