DEA Issues Public Safety Advisory on Fentanyl Mixed with Synthetic Tranquilizers and Opioids

The Drug Enforcement Administration issued a public safety advisory on May 12, 2026, warning that the illicit fentanyl supply is becoming increasingly dangerous through combination with synthetic substances not approved for human use. Law enforcement and public health officials are reporting fentanyl mixed with xylazine, medetomidine, nitazenes, and cy chlorphine — a cocktail that makes an already deadly drug supply more unpredictable and harder to reverse.

For people who use opioids and for the families who care about them, the advisory contains actionable information. The threat is serious, but the response is straightforward and does not require panic.

What the DEA Is Reporting

The advisory describes a shift in how illicit drugs are being manufactured and distributed. Fentanyl — already the primary driver of overdose deaths in the United States — is now frequently combined with additional synthetic compounds that users may not know are present.

Xylazine and medetomidine are veterinary sedatives. Xylazine has been present in the illicit opioid supply for several years, particularly in the Northeast and Mid-Atlantic regions. Medetomidine, sometimes referred to as "rhino tranq" because of its use in large animal veterinary medicine, is a newer adulterant with similar effects. Both drugs are not opioids. They do not respond to naloxone.

Nitazenes and cychlorphine are synthetic opioids that are not regulated for medical use. The DEA has identified 22 unique nitazene compounds since 2020, with 21 classified as Schedule I controlled substances. These compounds can be significantly more potent than fentanyl on a per-milligram basis. Unlike the veterinary sedatives, nitazenes do act on opioid receptors — but their extreme potency means that multiple doses of naloxone may be required to reverse their effects.

The result is a drug supply where a single batch may contain multiple substances with different mechanisms of action, different durations, and different responses to the standard overdose reversal medication.

Why This Changes Overdose Response

The core challenge with these combinations is reduced reversal effectiveness. When fentanyl is mixed with xylazine or medetomidine, naloxone will still reverse the opioid component — but the sedative component remains. The person may still be unconscious, breathing may remain suppressed, and the risk of death persists even after naloxone administration.

With nitazene or cychlorphine mixtures, naloxone can work, but the dose required may be higher than what is typically available in community settings. The standard two-dose naloxone kit may not be sufficient.

There is also the risk of re-narcotization. With high-potency synthetic opioids that have longer half-lives than naloxone, the person can begin to overdose again as the naloxone wears off — even after they have woken up. This is why calling emergency services is essential in every overdose situation, regardless of whether naloxone appears to work initially.

Recognizing an Overdose with These Adulterants

The presentation of an overdose involving these synthetic cocktails may differ slightly from a straightforward opioid overdose:

Profound sedation — the person may be extremely difficult to wake, beyond what is typical for opioid intoxication.
Slowed or stopped breathing — this remains the hallmark of opioid overdose, but may persist even after naloxone if sedatives are present.
Severe skin changes — xylazine in particular has been associated with severe soft tissue wounds and infections, sometimes called "xylazine wounds." These may appear as necrotic patches, often on the extremities.
Prolonged unconsciousness — the person may remain unresponsive for an extended period, even with naloxone administration.
Hallucinations or agitation — medetomidine has been associated with hallucinations and periods of immobility mixed with agitation.

If you suspect an overdose, the presence of any of these additional features should not change the initial response — but it should reinforce the importance of calling 911 immediately.

What to Do in an Overdose Emergency

The sequence of response remains the same, with emphasis on persistence and additional support:

Call 911 immediately. State that you suspect an overdose involving unknown substances. Most states have Good Samaritan laws that protect callers from prosecution for simple possession.
Administer naloxone. Give one dose in one nostril (or per the device instructions). Even if sedatives are present, reversing the opioid component is still life-saving.
Begin rescue breathing. Tilt the head back, lift the chin, and give one breath every five seconds. This is particularly important if the person is not breathing adequately — naloxone alone may not be enough if xylazine or medetomidine are involved.
Give additional naloxone doses if there is no response within 2–3 minutes. Continue every 2–3 minutes until the person is breathing on their own or emergency services arrive. With high-potency synthetics, three or more doses may be necessary.
Place the person in the recovery position — on their side with the upper knee bent — to prevent aspiration if they vomit.
Stay with the person until EMS arrives. Do not leave them alone, even if they appear to recover. Re-narcotization can occur as naloxone wears off.

If the person is not breathing and you are unable to provide rescue breathing, focus on naloxone administration and chest compressions if you are trained in CPR. Any intervention is better than none.

The Specific Risk of Medetomidine

Medetomidine deserves particular attention because it is newer to the illicit supply and less familiar to both users and responders. Like xylazine, it is an alpha-2 adrenergic agonist used in veterinary medicine. In humans, it causes:

Deep sedation and unconsciousness
Respiratory depression (slowed or stopped breathing)
Low blood pressure and slow heart rate
Hallucinations and disorientation upon waking
Prolonged periods of immobility

Because it is not an opioid, naloxone has no effect on medetomidine intoxication. The only effective response is supportive care — rescue breathing, maintaining airway patency, and emergency medical treatment. In veterinary settings, the antidote is atipamezole. This drug is not widely available in human emergency medicine, which makes prevention and rapid emergency response even more critical.

Harm Reduction Strategies

For people who continue to use opioids from unregulated sources, several strategies can reduce risk:

Never use alone. Have someone present who is not using, who has naloxone, and who knows how to use it.
Start with a small amount. Test the batch with a smaller dose than usual to gauge potency.
Have multiple naloxone doses available. Given the potency of current adulterants, having four to six doses is more appropriate than the standard two.
Use fentanyl test strips. While strips will not detect xylazine, medetomidine, or nitazenes directly, a positive result for fentanyl is still a warning that the product is not what it was sold as.
Seek drug-checking services where available. Some jurisdictions offer laboratory-based testing that can identify a broader range of substances.
Know the signs of xylazine-related wounds. Seek medical care immediately for any unexplained skin changes, necrosis, or infections — these can progress rapidly and lead to serious complications including amputation.

Where to Get Naloxone

Naloxone remains the most important tool for preventing overdose death, even with these new adulterants. Access points include:

Pharmacies. All 50 states allow naloxone to be dispensed without an individual prescription through standing orders or pharmacist prescribing. Most insurance plans, including Medicaid, cover the cost.
Local health departments. Many distribute naloxone free of charge along with training.
Harm reduction programs. Syringe services programs and other community-based organizations often provide naloxone and training.
NEXT Distro (nextdistro.org) — a national mail-order program that ships naloxone free to most U.S. addresses.
SAMHSA's National Helpline — 1-800-662-HELP (4357) can refer to local naloxone distribution programs.

Getting Help for Substance Use

If you or someone you love is using opioids and wants to explore treatment options:

SAMHSA's National Helpline: 1-800-662-HELP (4357). Free, confidential, 24/7, available in English and Spanish.
988 — the Suicide and Crisis Lifeline — also handles substance use crises and can connect callers with local resources.
SAMHSA's Find Treatment (findtreatment.gov) — a searchable directory of accredited treatment facilities by ZIP code.

Medication-assisted treatment with buprenorphine, methadone, or naltrexone remains the most effective intervention for opioid use disorder. The expansion of telehealth buprenorphine prescribing has made starting treatment more accessible in many parts of the country. You do not need to be ready for residential treatment to begin — a primary care visit, a call to a helpline, or a conversation with a harm reduction program is a legitimate first step.

The Bottom Line

The DEA advisory is a reminder that the illicit drug supply continues to evolve in dangerous directions. The combinations of fentanyl with synthetic sedatives and ultra-potent synthetic opioids create a situation where standard overdose response may need to be more aggressive and more persistent.

But the fundamental principles remain unchanged: carry naloxone, use with someone else present, call 911 in any suspected overdose, and seek medical care. These steps — even when imperfect — save lives. The goal is not to eliminate all risk, which is impossible in an unregulated supply, but to reduce the likelihood of the worst outcome and to keep people alive until they are ready for treatment.