Xylazine and Fentanyl: The Dangerous New Drug Combination Hitting San Diego

A dangerous new drug combination is spreading across the United States and reaching San Diego. Xylazine, a veterinary sedative never approved for human use, now contaminates approximately 25% of the fentanyl supply nationwide. This combination creates overdose situations that standard rescue methods cannot fully address, and it causes devastating physical complications that extend far beyond typical opioid risks.

At Amity San Diego, we recognize the urgent need for awareness about this emerging threat. Understanding xylazine contamination could save your life or the life of someone you love.

What Is Xylazine?

Xylazine is a non-opioid sedative and muscle relaxant approved exclusively for veterinary use in horses, cattle, and other large animals. Veterinarians use it to sedate animals before procedures. The drug has never received FDA approval for human use because of its dangerous effects on blood pressure, heart rate, and consciousness.

On the street, xylazine goes by names like "tranq" or "tranq dope" when mixed with fentanyl. Drug suppliers add it to fentanyl because it extends the high and adds sedative effects that users describe as more intense. The problem is that most people buying street opioids have no idea xylazine is in their supply.

The DEA has classified the fentanyl-xylazine combination as an emerging threat to the United States. Unlike fentanyl, xylazine is not a controlled substance at the federal level, which makes it easier and cheaper for drug suppliers to obtain.

The January 2026 Mount Sinai Research: Heart Dangers Confirmed

Research published in January 2026 by Mount Sinai researchers provided critical new evidence about the cardiac dangers of xylazine-fentanyl combinations. The study documented a clear link between xylazine-fentanyl use and bradycardia, a dangerous slowing of the heart rate.

Bradycardia caused by xylazine can drop heart rates to dangerously low levels, reducing blood flow to vital organs including the brain. Combined with the respiratory depression caused by fentanyl, this creates a dual threat where both breathing and heart function become compromised simultaneously.

The research found that xylazine's effects on the cardiovascular system create a more complex medical emergency than fentanyl alone. Emergency responders and medical professionals need to recognize xylazine involvement quickly to provide appropriate care.

Why Narcan Cannot Save You From Xylazine

Narcan (naloxone) has saved countless lives by reversing opioid overdoses. The medication works by blocking opioid receptors in the brain, rapidly reversing the respiratory depression that makes opioid overdoses fatal.

However, Narcan only works on opioids. Xylazine is not an opioid.

When someone overdoses on fentanyl contaminated with xylazine, Narcan can reverse the fentanyl effects but leaves the xylazine sedation untouched. The person may still remain unconscious, continue experiencing dangerous drops in blood pressure and heart rate, and face ongoing medical risk even after Narcan administration.

This limitation means that:

• Bystanders may believe Narcan failed when it actually reversed the opioid component but not the xylazine
• Prolonged unconsciousness continues even after successful Narcan administration
• Medical intervention beyond Narcan becomes necessary to address xylazine effects
• Delayed medical care becomes more dangerous because people may not recognize the need for additional treatment

Anyone carrying Narcan should still use it during suspected overdoses, as reversing the fentanyl component remains critical. However, calling 911 immediately is essential because xylazine requires additional medical support.

Severe Skin Wounds and Necrosis

Beyond overdose risk, xylazine causes severe physical complications that distinguish it from other drug adulterants. Users develop painful skin ulcers and necrosis (tissue death) that can occur at injection sites or even in areas distant from injection.

These wounds:

• Progress rapidly from small sores to deep, open wounds
• Resist healing even with proper wound care
• Lead to serious infections including bone infections
• Sometimes require amputation when tissue damage becomes too severe
• Develop regardless of injection technique or hygiene practices

The mechanism behind xylazine-related wounds is not fully understood, but researchers believe the drug constricts blood vessels and damages tissue in ways that prevent normal healing. Some users develop wounds even when smoking or snorting drugs containing xylazine, though injection carries the highest risk.

These wounds serve as a visible warning sign that xylazine exposure is occurring, though by the time wounds appear, significant tissue damage may have already occurred internally.

Xylazine Is Spreading to San Diego

Xylazine contamination began primarily in the Northeast, particularly in Philadelphia, where it became endemic in the street drug supply years ago. However, the contamination has steadily moved westward across the country.

San Diego faces particular vulnerability because:

• Fentanyl dominates the local opioid supply, having largely replaced heroin on the streets
• Proximity to the border means direct access to drug supply chains
• High demand for opioids creates economic incentive for suppliers to stretch products with adulterants
• Xylazine is legal and cheap to obtain compared to fentanyl itself

California health officials have documented xylazine in the state's drug supply, and the contamination continues to increase. Anyone using street opioids in San Diego should assume potential xylazine exposure with every use.

Why Professional Medical Detox Is Critical

Withdrawal from xylazine-contaminated fentanyl presents unique challenges that make professional medical detox essential rather than optional.

Standard opioid withdrawal is predictable and, while extremely uncomfortable, rarely life-threatening for otherwise healthy individuals. Adding xylazine changes this equation significantly.

Xylazine withdrawal symptoms include:

• Severe anxiety and agitation beyond typical opioid withdrawal
• Dangerous spikes in blood pressure
• Rapid heart rate fluctuations
• Intense physical discomfort that standard comfort medications may not address
• Extended duration of acute symptoms

The unpredictable nature of xylazine withdrawal means that symptoms can escalate suddenly in ways that require immediate medical intervention. Home detox or medically unsupervised detox attempts become significantly more dangerous when xylazine is involved.

Medical detox facilities can:

• Monitor vital signs continuously for dangerous fluctuations
• Adjust medications in real-time to address emerging symptoms
• Provide immediate intervention if complications arise
• Use medications specifically targeted to xylazine withdrawal effects
• Ensure comfort while maintaining safety throughout the process

Harm Reduction: Testing Your Supply

While treatment remains the path to safety and recovery, harm reduction strategies can reduce risk for people who are not yet ready for treatment.

Fentanyl test strips detect the presence of fentanyl in drug supplies before use. These strips are widely available and can prevent accidental fentanyl exposure for people who believe they are using other substances.

Xylazine test strips have recently become available and can detect xylazine contamination. These strips represent an important advance in harm reduction because they allow users to identify xylazine exposure before use.

Testing does not make drug use safe, but it provides information that can inform decisions and potentially prevent the most dangerous exposures. Many harm reduction organizations in San Diego County distribute both types of test strips.

Additional harm reduction practices include:

• Never use alone so someone can call 911 and administer Narcan if needed
• Start with small test doses to gauge potency and effects
• Carry Narcan and ensure others nearby know how to use it
• Know the signs of xylazine-related wounds and seek medical care early

Treatment After Detox: Outpatient and IOP at Amity San Diego

Once medical detox is complete, ongoing treatment becomes essential for building the foundation of lasting recovery. Detox addresses physical dependence but does not treat the underlying addiction.

Amity San Diego provides comprehensive outpatient treatment services designed to follow medical detox:

Intensive Outpatient Program (IOP) offers structured treatment with multiple sessions per week while allowing you to maintain work, family, and other responsibilities. IOP provides:

• Group therapy with peers who understand addiction recovery
• Individual counseling to address personal triggers and underlying issues
• Education about addiction, relapse prevention, and healthy coping strategies
• Family programming to rebuild relationships damaged by addiction
• Flexible scheduling including evening options

Outpatient Treatment provides ongoing support for people who have completed IOP or need a less intensive level of care. Regular therapy sessions help maintain recovery gains and address challenges as they arise.

Dual Diagnosis Treatment addresses co-occurring mental health conditions that often accompany substance use disorders. Depression, anxiety, trauma, and other conditions require integrated treatment alongside addiction care.

Take Action Now

Xylazine contamination represents a serious escalation in the dangers of street opioid use. The combination with fentanyl creates overdose situations that Narcan cannot fully reverse, and the drug causes devastating physical complications including severe wounds and dangerous heart effects.

If you or someone you love is using street opioids, the safest path forward is professional treatment. Medical detox provides safe withdrawal management, and comprehensive outpatient treatment at Amity San Diego builds the skills and support needed for lasting recovery.

Call Amity San Diego at (888) 666-4405 for a confidential conversation about treatment options. Our team understands the unique challenges of xylazine-fentanyl addiction and can help you find the right path to recovery.

Recovery is possible. The first step is reaching out for help.

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Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider for personalized recommendations. If you suspect an overdose, call 911 immediately.