03 Feb 2026
The Surrey Substance User Partnership has shared that recent testing of heroin samples from people who use substances in Slough has confirmed the presence of Xylazine and Fentanyl in the local supply. This is an extremely dangerous combination that carries a high risk of overdose and serious harm.
Xylazine is a tranquilliser, pain reliever, and central nervous system depressant that is FDA-approved for use in veterinary medicine. Xylazine is largely used as an adulterant to other substances such as heroin, synthetic opioids, cocaine, counterfeit codeine and diazepam tablets, THC vapes and others.
Xylazine is usually found mixed with other drugs and can be consumed without knowledge that it is present. It is particularly dangerous to mix with other depressants and those that suppress breathing, such as alcohol, benzodiazepines, or other opioid drugs, and can have fatal side effects as it increases the risk of overdose.
Xylazine can make people drowsy and cause breathing, heart rate, and blood pressure to slow to dangerously low levels (which could lead to coma and/or death). The use of Xylazine can cause painful skin and muscle sores all over the body. If left untreated, they can grow and become infected, leading to patches of dead and dying tissue.
Other physical effects of Xylazine can include:
Shallow/difficulty breathing.
Low/irregular heart rate.
Low blood pressure.
Drowsiness.
Low body temperature.
Severe skin ulcers/wounds that can lead to amputation if not treated.
High blood sugar.
Excessive thirst.
Constricted pupils.
Xylazine is not an opioid, so naloxone will not reverse its effects. However, because it is often mixed with opioids, naloxone should still be administered in a suspected overdose, as it can reverse the opioid component and may still save a life.
Share this alert with those who might use similar substances or work with those who do, and encourage them to seek help and advice. Ensure those who need to be are aware of the signs of overdose and the appropriate emergency response, including the use of naloxone where indicated. Report any unusual drug-related presentations or adverse reactions through local reporting channels. Stay alert and share this information.
Raising awareness can prevent harm and save lives.
