Kratom: What It Is, Regulation and Risks

Quick answer

Kratom is a tropical tree, Mitragyna speciosa, native to Southeast Asia. Its leaves contain compounds that act on opioid receptors in the brain. The FDA has warned consumers not to use kratom because of risks including liver toxicity, seizures and substance use disorder. [1] It has not been shown to be safe and effective for any medical use. [2] Evidence labels used here: approved medicine (none exists), insufficient evidence, evidence of harm (case reports and regulator warnings), marketing claim.

Traditional use

In Southeast Asia, people have chewed kratom leaves or made them into tea to fight fatigue and improve work productivity. It has also been used in religious ceremonies and for symptoms such as pain and diarrhea, sometimes as a substitute for opium. [3] Anthropologists report use for hundreds of years as a multi-purpose traditional remedy. [2]

What is in it

Kratom leaves contain more than 50 alkaloids. Most research focuses on mitragynine and 7-hydroxymitragynine (7-OH), which bind to the same brain receptors as opioid drugs such as codeine. [1] 7-OH is a minor part of natural leaf (under 2% of alkaloids) but is much more potent at the mu-opioid receptor than mitragynine. [1] People who use kratom report stimulant-like effects (energy, alertness, fast heartbeat) and effects like opioids and sedatives (relaxation, pain relief, confusion). [3]

Regulatory status in the United States

• The FDA says no prescription or over-the-counter drug containing kratom is legally on the market, and that kratom is not lawfully marketed as a drug, dietary supplement or food additive in conventional food. [1]
• The FDA has seized some shipments of kratom products labeled as dietary supplements [3] and acts against companies making false or misleading claims about unproven benefits. [1]
• The DEA has listed kratom as a "drug of concern," but kratom compounds were not on the federal controlled-substance schedule as of the NIH pages read (NCCIH page updated 2022). [3]
• NIDA says kratom products are legal and accessible online and in stores in many areas of the US, and that kratom has been banned or restricted in several countries. [2] The FDA notes that states may have their own rules. [1]

Laws change and this is not legal advice. Check current federal, state and local rules.

What research shows

Pain, mood, opioid withdrawal: insufficient evidence. The FDA says there are animal studies but few well-designed human studies. [1] Very little research in people has evaluated kratom's health effects, and it has not been shown safe and effective for opioid withdrawal or any other medical use. [3] Approved, proven medicines exist for opioid withdrawal; ask a clinician. [2]

The FDA also notes a well-designed human abuse-potential study had not yet been completed at the time of its page, and has funded one. [1]

Risks and adverse effects

• Common effects: nausea, constipation, dizziness and drowsiness. [3]
• Serious effects, uncommon: seizures, high blood pressure and liver problems. [3] A 2026 systematic review found 32 published cases of kratom-associated liver injury, mostly cholestatic (bile flow), usually improving after stopping, with 4 patients progressing to liver transplantation. Most cases were single reports with other substances involved and unclear exposure details. [4]
• Seizures: a systematic review found 20 reported patients, but only one had a lab-confirmed kratom marker, so causation could not be shown. [5]
• Dependence and withdrawal: the FDA describes cases that met criteria for substance use disorder, with cravings, tolerance and withdrawal. [1] NIDA says studies suggest mild to moderate withdrawal after stopping regular use, and that how often a use disorder develops needs more research. [2]
• Deaths: fatal overdose from kratom alone appears extremely rare, but deaths have been linked to kratom taken with other drugs. [2][3] The FDA says kratom's contribution in those cases is unclear. [1]
• Breathing: neither kratom leaf nor mitragynine appears to cause the breathing suppression typical of opioid overdose, but in lab models 7-OH can. [2]

Special groups and quality

The FDA is aware of newborns who showed withdrawal signs (jitteriness, irritability, muscle stiffness) after prolonged exposure to kratom before birth. [1] Some kratom products have been contaminated with Salmonella or heavy metals. [1][3] Long-term effects are not well understood. [2]

How to read claims

Be cautious of products that claim to treat pain, anxiety, depression or opioid withdrawal. The FDA acts against products that make false or misleading claims about unproven benefits. [1]

Related reading

Kava, how interactions work, liver safety and supplements and talking with a health professional. For poisoning emergencies call 911 or Poison Help at 1-800-222-1222 in the US; see poison help by country.