Opioids Laced With Xylazine: Effects & Risks

Illicit sources of opioids, including illegally manufactured fentanyl and heroin, are often cut with other substances, which can make them especially risky to use.¹ Xylazine is a dangerous substance that has been increasingly added to opioids (as well as other substances) and is significantly contributing to the opioid overdose epidemic.^1,2

Keep reading to learn more about xylazine, including the risks of opioids mixed with xylazine, xylazine overdose, whetherxylazine is itself addictive, and how to find treatment for opioid misuse and addiction.

What is Xylazine?

Xylazine is not approved for human use in the U.S.² Xylazine is a non-opioid animal tranquilizer that is FDA-approved for veterinary use only.^2,5 Xylazine has sedative, analgesic, and muscle relaxant properties, and  is currently used by veterinarians to treat horses and deer for a variety of medical needs, including anesthesia for a surgical procedure, calming rambunctious animals, and pain management after an injury or surgery.⁴ However, while this drug has legitimate medical uses, illicit use of this drug has been growing.³

Xylazine was originally synthesized in 1962 and researched for its potential uses as an analgesic, sleep aid, and anesthetic in humans, but clinical trials were discontinued due to adverse effects, including severe hypotension (low blood pressure) and central nervous system (CNS) depression.⁴

While it is not currently a controlled substance under the U.S. Controlled Substances Act, the FDA and other federal agencies have expressed growing, serious concerns about xylazine’s potential dangers in humans.^1,3 Although xylazine is not approved for use in humans, it is commonly mixed with other illicitly used substances, such as heroin, fentanyl, and cocaine.⁴ It may be added to these substances to increase the high or euphoric effects.²

People may knowingly or unknowingly use xylazine. For example, they may be unaware that xylazine has been added to drugs they’ve purchased on the street, but some people may also purposely misuse xylazine on its own or in combination with other drugs.^2,4 Illicit sources of xylazine are sometimes referred to as “tranq” or “tranq dope.”⁶

Effects of Xylazine

Xylazine can depress certain nervous system functions, leading to drowsiness, amnesia, and dangerous slowing of vital processes such as heart rate and breathing.² Xylazine is reportedly used with illicit opioids in attempt to prolong the euphoric effects of those drugs.^2,3  

While research into its impact on humans is ongoing, there is evidence that people can experience a variety of xylazine effects, some of which can be serious.⁸

Some of the initial adverse effects of xylazine may include:³

• Dry mouth.
• Drowsiness.
• An initial rise in heart rate and blood pressure.

These effects may then be followed by:³

• Low blood pressure.
• Slowed heart rate.
• Abnormal heart rhythms.
• A drop in body temperature.
• Respiratory depression.
• Loss of consciousness and coma.

Risks of Opioids Mixed with Xylazine

Though the full risks and effects of xylazine and opioids in combination are not yet fully understood, experts know that mixing opioids and xylazine can be very dangerous and potentially life-threatening.⁶ Opioids laced with xylazine most commonly include fentanyl and heroin but can also include other illicitly manufactured synthetic opioids.^3,8

The risks of opioid/xylazine misuse can include:

• Soft-tissue injuries/necrosis as a result of intravenous use.³ Injecting xylazine or drug mixtures containing xylazine can lead to infection and soft tissue injuries that lead to necrosis (death) of these areas, which can potentially necessitate amputation and may be life-threatening.^3,6
• Increased CNS/respiratory depression.² Although xylazine is not an opioid, it can contribute to dangerously slowed breathing, heart rate, and decreased blood pressure, and increase the effects of life-threatening overdose when combined with opioids.²
• Complications during opioid withdrawal management.⁶ Xylazine dependence may develop, and the drug may be associated with its own withdrawal syndrome. Such withdrawal symptoms would not respond to the types of medications that are typically used to manage opioid withdrawal, such as buprenorphine and methadone.⁶ It’s been reported that people can suffer from severe xylazine withdrawal symptoms that may be more serious than those associated with heroin, including severe chest pain and seizures.^3,6
• Cardiovascular effects.⁹ These risks, including transient hypertension followed by severe hypotension, can occur from xylazine use alone but can significantly increase when combined with opioids.⁹

Can You Overdose on Xylazine?

Yes, xylazine overdose can (and does) occur, and it is a serious risk related to opioid/xylazine use because it can be deadly.² The risks of overdose are significantly increased when xylazine is combined with other substances, such as opioids.² In addition, the FDA has indicated serious concerns that naloxone, the opioid overdose reversal drug, may not be effective for xylazine overdose.¹

Xylazine overdose symptoms can overlap and resemble some of those associated with opioid overdose alone.¹ Some symptoms of a combined opioid and xylazine overdose may include include:^2,9

• Diminished muscle reflexes.
• Abnormal weakness.
• Ataxia (e.g., uncoordinated movements, slurred speech, etc.)
• Pronounced sedation.
• Disorientation.
• Vomiting.
• Constricted pupils.
• Slow heart rate
• Low blood pressure.
• Respiratory depression.

An overdose can be fatal.⁹ If you think that someone is experiencing an overdose, you should administer naloxone regardless of whether you suspect opioid involvement and call 911 right away.¹

Not all jurisdictions currently test for xylazine in postmortem toxicology, so it’s probable that many xylazine-involved overdoses have gone undetected.³ However, the DEA reports that all four U.S. census regions have experienced a significant increase in xylazine-positive overdoses from 2020-2021.³ The Centers for Disease Control and Prevention also reports that out of 21 jurisdictions, the monthly percentage of Illegally manufactured fentanyl (IMF) involved deaths with xylazine detected increased 276% from January 2019 (2.9%) to June 2022 (10.9%).⁸

Is Xylazine Addictive?

Though there is some evidence for patterns of xylazine misuse on its own in Puerto Rico, the question of whether the drug itself is addictive, or is somehow contributing to a phenomenon of combined drug addiction, hasn’t been thoroughly determined.³

Whether xylazine is addictive or not, the substances it is cut with often are. For example, as mentioned above, xylazine is increasingly prevalent in opioids and other illicit substances that have addictive potential, such as cocaine.² Becoming addicted to opioids or other drugs can therefore increase a person’s likelihood of consuming xylazine either knowingly or unknowingly and increase their overall risk.² The addictive potential of xylazine on its own is not considered to be the primary issue at the present moment, but the risks associated with polysubstance misuse and addiction remain major concerns.⁹

Opioid Addiction Treatment in California

If you or a loved one are concerned about xylazine or opioid misuse or addiction, please know that treatment is available. Laguna Treatment Hospital provides opioid addiction treatment on different levels of rehab that include our medical detox facility in Orange County and residential inpatient care that can help you get started on the path to recovery.

If you’re ready to start the recovery process, please call our free, confidential helpline at to speak with one of our caring admissions navigators about your rehab options. You can also learn more about rehab admissions, how to pay for rehab, and using insurance to pay for rehab.

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