What is xylazine?


Xylazine is a drug primarily used in veterinary medicine as a sedative, analgesic, and muscle relaxant for animals. It is an alpha-2 adrenergic agonist that produces effects similar to those of opioids. However, xylazine is not an opioid and has no approved medical use for humans. Despite this, it has been increasingly found as an adulterant in illicit drugs, such as heroin and fentanyl, which poses significant risks to users. Most notably, xylazine can complicate overdoses due to the fact that it isn’t itself an opioid and doesn't respond to common antidotes for opioid overdose, like naloxone.

Historical context

Xylazine was first synthesized in the 1960s and has been used in veterinary medicine for decades. In recent years, it has emerged as a dangerous adulterant in illicit drugs, particularly in heroin and fentanyl. While opioids like fentanyl produce a powerful high, the euphoric feelings are shorter-lived than those offered by other opioids like heroin. That means that PWID have to inject more frequently, which can be expensive, inconvenient, and risky. Adding xylazine, however, seems to extend the high for PWID. Its use in this context can lead to severe health risks and has been associated with an increased risk of overdose. In particular, the injection use of xylazine mixed with other drugs poses a high risk for skin ulcers, severe tissue wounds and necrosis, possibly resulting in a need for amputation.

Medical formulation

Xylazine is typically available as an injectable solution for veterinary use. It is not approved for human use and is not available in medical formulations for human consumption.

How long does xylazine stay in your system?

There is limited information on the half-life and duration of xylazine in humans, as it is not intended for human use. In animals, the half-life of xylazine is approximately 30 to 90 minutes, depending on the species. However, the half-life and elimination time in humans may differ.

Street names

Sleep cut, Tranq


As a veterinary medication, xylazine is usually found as a clear, colorless injectable solution. When used as an adulterant in illicit drugs, it may not be distinguishable from other substances in the mixture.

Warning: Consuming illicit drugs, including pressed pills, may result in unintended fentanyl exposure, leading to potentially fatal consequences. Exercise caution and consider using fentanyl testing strips to identify the presence of this dangerous substance in street drugs.

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