Xylazine produces heavy sedation, pain relief, and sometimes euphoria. It is a veterinary tranquilizer with no approved use in humans, but it has become a common adulterant in the illicit drug supply, particularly mixed with fentanyl. People exposed to it often describe an intense, prolonged “nod” that feels different from opioids alone, lasting hours longer and carrying a distinct set of physical effects and risks.
The Immediate Sensation
Xylazine works by suppressing the release of stress hormones (norepinephrine and epinephrine) in the brain. This creates a deep wave of sedation, muscle relaxation, and pain relief. Some users also report a feeling of euphoria. One Reddit user in a study published in the Journal of Addiction Medicine described it bluntly: “I fucking LOVED xylazine… I was so upset if my fetty wasn’t cut with it.”
But the sedation is extreme. In that same study of 48 people who self-reported xylazine experiences, 81% described prolonged sedation or episodes of passing out. The feeling is often described as being knocked out rather than pleasantly high. Your heart rate slows, your blood pressure drops, your body temperature can fall, and your mouth goes dry. Some people experience disorientation, slurred speech, constricted pupils, and a loss of coordination. Because xylazine is not an opioid, these effects layer on top of whatever opioid is also present, creating a sedation that feels heavier and harder to control than fentanyl alone.
How It Differs From an Opioid High
Opioids like fentanyl produce sedation primarily by acting on opioid receptors. Xylazine hits a completely different system. It belongs to the same drug class as clonidine (a blood pressure medication), and its sedative effect comes from dampening the brain’s alertness signals rather than flooding its reward pathways. In practice, this means the “high” from xylazine feels less warm or euphoric than a pure opioid experience and more like being pulled under into unconsciousness.
The combination is what makes xylazine-laced fentanyl so distinct. Users report a longer, deeper nod. Where fentanyl’s peak effects are intense but relatively short, xylazine can extend sedation for hours. Symptoms of xylazine exposure can begin within 15 minutes and, in cases of significant exposure, the sedative effects can persist for days. This extended unconsciousness is dangerous on its own: people may be unresponsive for long periods, lying in positions that cut off blood flow to limbs, or unable to be roused even with naloxone (Narcan), which reverses opioids but has no effect on xylazine.
Physical Effects on the Body
Beyond sedation, xylazine creates a recognizable set of physical changes. Heart rate slows noticeably. Blood pressure drops, sometimes severely. Body temperature falls. Blood sugar can rise. These cardiovascular effects are part of why xylazine-involved overdoses look different from opioid-only overdoses: the person may still have a pulse (first responders found a pulse more often in xylazine-involved overdose deaths compared to fentanyl-only deaths) but remain deeply unconscious with dangerously slow breathing.
One of the most distinctive physical consequences is skin damage. About 43% of users in the Reddit study reported increased skin wounds or infections. Xylazine constricts blood vessels near the skin, reducing blood flow. Over time, this leads to chronic, progressive ulcers that can appear anywhere on the body, not just at injection sites. People who snort xylazine-laced drugs have also reported skin wounds, suggesting the damage is partly a systemic effect rather than purely from needles. These wounds typically start as pale, discolored patches of skin that gradually open into large, foul-smelling ulcers with dead tissue at the center. They heal poorly and are prone to infection. In documented cases, ulcers have appeared across both forearms and knees simultaneously, some reaching 4 centimeters across.
What Withdrawal Feels Like
Xylazine withdrawal is still being characterized by researchers, but people who have gone through it describe it as severe. In the Reddit study, 53% of participants reported experiencing withdrawal from xylazine, and 57% said xylazine made withdrawing from other substances worse.
Anxiety is the dominant symptom, reported by 91% of those who experienced withdrawal. Body aches affected 63%, and cravings affected 49%. Irritability and restlessness are also common. Unlike opioid withdrawal, which follows a well-known timeline, xylazine withdrawal can include a dangerous spike in blood pressure, essentially a rebound from the drug’s blood-pressure-lowering effects. This makes stopping abruptly riskier than with most other substances in the illicit supply.
Perhaps the most concerning finding from user reports is the psychological toll. Fully 74% of participants in the Reddit study reported depressed mood as an adverse effect of their xylazine use, a rate far higher than what’s typically associated with opioids alone.
Why People Don’t Always Know They’ve Taken It
Xylazine is not a controlled substance in the United States, despite being authorized only for veterinary use. It is cheap, widely available, and increasingly mixed into the drug supply without buyers’ knowledge. Because it extends and deepens the sedation from fentanyl, some dealers add it to make their product seem stronger. Many people who experience xylazine’s effects have no idea that’s what they’ve taken. They notice only that the high feels heavier, lasts longer, that they “went out” for hours, or that wounds on their skin won’t heal. By the time they connect these experiences to xylazine, they may already be physically dependent on it.