By Lauren Smith

Updated: 14 March 2024 & medically reviewed by Dr. Kimberly Langdon

Tranq dope is the street name for the non-opioid veterinary tranquilizer xylazine, a powerful sedative cropping up in supplies of fentanyl and heroin in the Northeast. It can prolong the short-lived high of fentanyl but comes with a heightened risk of overdose and harrowing side effects like skin ulceration and infection, sometimes severe enough to require amputation.

What is Tranq Dope?

What is Xylazine?

Xylazine is a non-opioid tranquilizer used as a sedative, anesthetic, muscle relaxant, and painkiller in animals such as horses, cattle, deer, sheep, dogs, cats, rats, and elk.[5]

Xylazine has no FDA-approved use in humans. When manufacturer Bayer studied it in humans in the 1960s, xylazine was found to cause severe side effects, including very low blood pressure and severe depression of the central nervous system.[6]

What is tranq dope?

Tranq dope, or tranq, is the street name for xylazine, a non-opioid tranquilizer used in veterinary medicine. While it’s occasionally used recreationally on its own, it’s most commonly encountered as an adulterant and add-on in supplies of other illicit drugs.[1] 

Over the last few years, xylazine has increasingly been detected in supplies of illicit drugs and implicated in overdoses of those drugs in the United States, prompting the Food and Drug Administration (FDA) to issue a warning in November 2022. The watchdog warned that xylazine has primarily been identified in combination with heroin and fentanyl but has also turned up in supplies of the stimulants cocaine and methamphetamine.[2] It also occasionally turns up in cannabis and adulterated benzodiazepine pills.[3]

Drugs containing xylazine may be sold under the street names tranq, tranq dope, zombie drug, sleep-cut, and Philly dope, the last one reflecting its early appearance in Philadelphia.[4] In Puerto Rico, it’s known as “anestesia de caballo” or horse anesthetic.[1]

How is xylazine used?

Beyond its approved use in veterinary medicine, xylazine is abused by humans for the euphoric, sedating effect it provides. Most commonly, it’s an additive to other drugs, especially the powerful opioid fentanyl. 

Some people deliberately take dope tranq with fentanyl, reportedly to prolong the opioid’s usually brief high. However, others are unaware that their drugs have been cut with tranq and aren’t prepared for its dangers.[7]

Dope tranq may also be added to the mixtures of opioids and stimulants known as speedballs to mitigate unpleasant side effects.

Dope tranq can be swallowed, snorted, inhaled, smoked, and injected into a muscle or vein.

What are the effects of xylazine in humans?

Xylazine, or dope tranq, can initially cause euphoria in humans, hence its abuse and presence in the drug supply. However, it quickly causes more severe and sometimes fatal effects, especially in overdose. These may be difficult to distinguish from an opioid overdose. However, the standard treatment for opioid overdose—the opioid antagonist naloxone (Narcan)—isn't effective against xylazine, so it’s crucial that xylazine be identified quickly in an overdose victim.

Immediate effects of dope tranq include: [8]

  • Depression of the central nervous system (CNS), causing sedation, drowsiness, and disorientation)

  • Slow breathing

  • bradycardia (slow heart rate)

  • Hypotension (low blood pressure)

  • Amnesia

  • Hypothermia (low body temperature)

  • Miosis (pinpoint pupils)

  • Blurred vision

  • Dizziness

  • Slurred speech

  • Fainting

  • Hyperglycaemia

  • Dry mouth

  • Coma

  • Death

Xylazine can leave users in a stupor deeper and more prolonged than that caused by opioids. This can leave them vulnerable to crimes such as theft and sexual assault.

Effects of xylazine last for eight hours but in the case of overdose can last for 72 hours. Xylazine is very dangerous: a review found 43 cases of xylazine intoxication in medical literature, of which around half (51%) were fatal and most of the non-fatal cases required medical intervention.[8]

Because it depresses breathing, xylazine increases the risk of overdose when taken alongside opioids, which also slow respiration.

What are the long-term effects of xylazine use?

Long-term effects of dope tranq use include:

  • Severe skin ulceration

  • Skin abscesses

  • Slow wound healing

  • Frequent, persistent skin infections

  • Necrosis

  • Amputation of limbs

These skin problems occur not just around the injection site, in the case of intravenous drug use, but throughout the body, especially the limbs. They’re thought to emerge because xylazine constricts blood vessels and also, by depressing heart rate, blood pressure, and breathing, reduces tissue oxygenation in the skin. Prolonged use increases this vasoconstriction and skin oxygenation deficit, leading to soft tissue infections.[9]

How prevalent is xylazine in the illicit drug supply?

Dope tranq has been detected with increasing frequency in the illicit drug supply in the United States, especially in the Northeast. 

Xylazine entered the US around 2006, first turning up in the opioid supply in Philadelphia. The city remains the capital of tranq use and in 2020 the drug was detected in 25.8% of overdose deaths. It was followed by Maryland (19.3% of overdose deaths in 2021) and Connecticut (10.2% in 2020).[10]

The situation has worsened in just the short few years since that data was collected. In 2023, medical toxicologists at Temple Health in Philadelphia reported that it was present in 90% of the city’s opioid supply.[11] The drug has also now been detected in at least 36 states and the District of Columbia.[3]

Xylazine is legal for veterinary use, its use only permitted by or on the orders of a licensed veterinarian.[12]

Xylazine isn’t controlled under the federal Controlled Substances Act. However, some states have acted to restrict access. New York State designated it a controlled substance in 2017.[13]

How do you treat xylazine overdoses?

Dope tranq isn’t an opioid so its effects, especially on breathing, cannot be reversed by the opioid rescue drug naloxone (Narcan). Its growing prevalence has raised concerns among first responders that Narcan will become less useful for saving lives during overdoses

Treatment is therefore supportive, with measures undertaken to maintain the patient’s blood pressure, heart rate, and airways.[14]

How to stay safe when using drugs that may contain xylazine

If you use opioids like fentanyl or other illicit substances, you may encounter dope tranq and you may not be aware of it. Drug users trying to avoid fentanyl have become accustomed to testing their supply with fentanyl test strips. However, no similar easy testing method for xylazine is available, although populations who use heroin and fentanyl say they would use it if it were.[15]

To stay safe when using drugs that may contain xylazine, you should:

  • When buying the drug, ask questions about what it is and what it may be cut with.

  • Don’t use drugs alone. Stay with a trusted and ideally sober friend who can monitor you for signs of overdose and raise the alarm.

  • Try a small amount of the substance first to see how it affects you.

  • Always keep naloxone with you and learn to use it. Although it may not reverse the effects of tranq, it can reverse the effects of opioids, which compound those of tranq.

  • Use clean needles. Although this can’t prevent the skin ulcers and infections associated with tranq, it can reduce their frequency.