Medetomidine Situation Summary

Medetomidine is currently in the U.S. illegal drug supply

Medetomidine is a sedative and not approved for use in people. Medetomidine is frequently found mixed with illegally made fentanyl and people may not know they are taking it.

If someone has regular exposure to medetomidine, they may experience severe withdrawal syndrome when they stop taking it. This may happen after someone is given an opioid overdose reversal medication, such as naloxone, during an overdose. Severe withdrawal syndrome can cause organ damage and often requires emergency or intensive care.

Detection is expanding geographically

• 2021: Medetomidine was first found in the drug supply with illegally made fentanyl.
• 2023-2024: Medetomidine reports submitted to the National Forensic Laboratory Information System (NFLIS) increased 950% (from 247 to 2,616) and continued to rise sharply to 8,233 in 2025.
• 2025: Among medetomidine reports submitted to NFLIS, the Northeast (52%) and Midwest (31%) had the most, followed by the South (17%) and the West (<1%).
• July 2025-December 2025: Provisional data shows that 10 of 20 testing sites detected medetomidine in more than a third of opioid positive drug product and paraphernalia samples. These sites were most often located in Northeastern states (n=5 of 5 sites), Midwestern states (n=4 of 6 sites), and Southern states (n=1 of 4 sites). All five sites from Western states detected medetomidine in opioid positive samples at low levels ranging from 2-8% of samples.
• October 2025-January 2026: Medetomidine continues to be detected in treated wastewater every week.
  

Percentage of opioid-positive drug product and paraphernalia samples positive for medetomidine across 20 sentinel sitesA: US region, July 2025 – December 2025 (Provisional data)B C

View Larger

• Northeast: 74.2% medetomidine positive (5 sites); 1 sites 26–50% of samples and 4 sites >50% of samples
• Midwest: 56.2% medetomidine positive (6 sites); 1 site <5% of samples, 1 site 10–25% of samples, 1 site 26–50% and 3 sites >50% of samples
• South: 30.1% medetomidine positive (4 sites); 3 sites 10–25% of samples and 1 site >50% of samples
• West: 3.8% medetomidine positive (5 sites); 3 sites <5% of samples and 2 sites 5–9% of samples

What CDC is doing

CDC supports states and local communities working to detect, prevent, and respond to health threats - including new threats like medetomidine in the drug supply. Health departments conducted laboratory testing of drug products and paraphernalia through CDC's Overdose Data to Action (OD2A) cooperative agreement or through testing by the National Institute of Standards and Technology (NIST).

What to do if someone is at risk

• Administer naloxone and call 911 If you think someone is having an opioid overdose.
• Use drug test strips to detect unknown substances that may be mixed in with illegal drugs. Drug test strips are available for some individual products such as fentanyl, xylazine, and medetomidine.
• Severe withdrawal symptoms can start quickly. If you think you or someone you know is in severe withdrawal, call 911 or take them to the hospital.

Clinicians

• Learn more from the Health Alert Network (HAN): Medetomidine in the U.S. Illegal Fentanyl Supply Increasing Risk for Overdose and Severe Withdrawal Syndrome.
• Consider medetomidine intoxication when a patient experiences prolonged sedation after a suspected opioid overdose continuing after naloxone administration.
• Consider medetomidine withdrawal when patients have tachycardia, severe hypertension, fluctuating alertness, tremor, chest pain, or intractable nausea and vomiting, or when patients do not improve after standard opioid withdrawal treatment.
• Consult with a toxicologist or call poison control at 1-800-222-1222.
• Contact the Health Resources & Services Administration-funded Substance Use Warmline for a free and confidential teleconsultation on substance use evaluation and management. Call 844-275-6222; (Monday–Friday, 7 a.m.–5 p.m. PT, excluding holidays).
• Notify your local or state health department of unusual overdoses or other adverse events, including signs of overdose or withdrawal that may involve medetomidine.