The opioid epidemic continues to rage across the United States, and in 2026, the dangers of opioid misuse increase as new adulterants make their way into counterfeit pills and street drugs.
- A 2025 study found that opioid and fentanyl use is more pervasive than previously thought, with 1 in 10 US adults reporting non-prescription opioid use.
- Illicit fentanyl is present in the majority of counterfeit pills and street drugs; fentanyl is responsible for 90% of fatal drug overdoses.
- In 2026, law enforcement and health officials are now warning of the dangers of medetomidine, a new adulterant present in counterfeit pills and street drugs that is shifting the opioid crisis and overwhelming emergency departments.
In Philadelphia, 160 hospitalizations occurred over a 3-day period. ICU beds are being filled by patients undergoing a withdrawal crisis from medetomidine. “Our ICUs have been overwhelmed,” Daniel del Portal, MD, senior vice president of medical operations and chief clinical officer of Temple University Health System in Philadelphia, told the New York Times.
What is Medetomidine?
In 2024, a veterinary sedative called medetomidine began adulterating fentanyl and heroin in major cities across the country.
Medetomidine is a powerful tranquilizer in a class of drugs used in veterinary medicine to sedate animals during procedures and examinations. Medetomidine is not approved for human use.
What makes medetomidine exceptionally alarming is its potency; it’s 100 to 200 times more powerful than xylazine, another veterinary sedative, which has been mixed into the fentanyl supply, resulting in significant harm over the past several years.
The first confirmed detection of medetomidine as a street drug adulterant occurred in Maryland in July 2022. By 2023, it began appearing in states including Pennsylvania, Missouri, Colorado, and California.
By November 2024, medetomidine was present in 87% of drug samples in Philadelphia.
As of early 2025, drug checking programs in Philadelphia found medetomidine in 72% of illicit opioid samples. Fentanyl remained present in 100% of tested samples.
Medetomidine is creating new challenges for healthcare providers, law enforcement agencies, and the individuals who are using counterfeit pills and illicit street drugs. This adulterant is also creating a new struggle for communities already devastated by the opioid epidemic.
Why is Medetomidine Added to Drugs?
Why are veterinary sedatives being mixed with fentanyl and other illicit opioid drugs? Adulterants like xylazine and medetomidine are added to drugs such as cocaine, heroin, and fentanyl to enhance the drug effects (adding sedatives can prolong the high for users) or increase the street value/ weight of the drugs.
When a substance is readily available, easy to obtain, and inexpensive to use, it can easily become a desirable adulterant, regardless of its impact on users.
As certain adulterants become regulated or harder to obtain, alternatives become attractive. When xylazine sale/ use became restricted in Pennsylvania, medetomidine may have emerged as an unrestricted replacement. The U.S. became the world’s largest importer of medetomidine in 2024, making the drug readily available through existing supply chains.
What are the Risks of Medetomidine Use?
Medetomidine creates life-threatening complications in two distinct phases: during active use and overdose, and during withdrawal.
Medetomidine Overdose Risks
When fentanyl is mixed with medetomidine, users are exposed to multiple central nervous system depressants at once, which increases the likelihood of overdose.
Mixing opioids and sedating drugs is six times more likely to lead to overdose death compared to the use of opioids alone, according to researchers from the University of Washington School of Public Health and the Washington State Department of Labor and Industries.
Medetomidine is a veterinary sedative designed to last for hours in medical settings where controlled doses are used. On the street, dosages are unknown, and the drug is combined with other substances; sedation can be so long-lasting that it can require hospitalization.
The effects of medetomidine can include:
- Profound and prolonged sedation
- Bradycardia - extremely low heart rate
- Hypotension - dangerously low blood pressure
- Respiratory depression - slowed or stopped breathing
- Peripheral vasoconstriction - narrowing of blood vessels
- Tremors and shaking
- Nausea and vomiting
Overdose Drugs Don’t Work on Medetomidine
Overdose drugs such as naloxone that can reverse the opioid component of an overdose don’t work on medetomidine. Naloxone may start a person breathing again after an overdose, but they can remain deeply sedated for hours due to medetomidine’s effects. They remain at risk for aspiration, continued respiratory depression, and other dangerous complications that can require emergency intervention.
Medetomidine Withdrawal Leading to Medical Crisis
Fentanyl-medetomidine mixtures can spur life-threatening withdrawal symptoms within a few hours.
Watch on YouTube: CBS Explores the Withdrawal Dangers of Medetomidine
Medetomidine withdrawal is severe, sudden, and can be life-threatening.
Between September 2024 and January 2025, 165 Philadelphia patients hospitalized for fentanyl withdrawal experienced complications now known as medetomidine withdrawal syndrome.
91% of those patients required admission to the intensive care unit. Nearly one quarter needed to be intubated.
The symptoms of medetomidine withdrawal include:
- Severe hypertension
- Rapid heart rate - tachycardia
- Intense anxiety and agitation
- Uncontrollable nausea and vomiting
- Violent shaking and tremors
- Waxing and waning alertness
Medetomidine withdrawal syndrome is resistant to the medications that typically work for opioid withdrawal. Standard protocols for opioid withdrawal don’t work, and symptoms can be so severe as to require ICU-level care.
Some patients have experienced complications from the extreme blood pressure swings, including myocardial infarction (a type of heart attack) and brain damage from sustained high blood pressure.
The medetomidine withdrawal process has created a separate crisis within the opioid crisis.
Medetomidine treatment is typically only available in hospital settings, particularly ICUs, and is not available in addiction treatment facilities. The CDC is responding by issuing health alerts and developing treatment guidance, but the drug supply moves faster than policy can keep up. The opioid crisis continues to evolve, and communities and advocates need to be aware of the changing risks associated with illicit opioid use.
Make a difference in your community:
- Be aware of medetomidine risks and symptoms.
- Share this post in your community or organization.
- Stop opioid diversion in your home and community: lock up powerful prescription meds.
