15 Apr 2026
Merton Public Health in Greater London has issued an urgent warning following multiple hospitalisations of young people under 18 linked to vape liquids containing synthetic cannabinoids (commonly known as spice). Laboratory testing has confirmed these substances are being sold in liquids that look like standard vape products.
Synthetic cannabinoids, also known as spice, are a group of drugs designed to mimic the effects of cannabis, but they can be anywhere from 5 to 100 times more potent than the chemical (known as THC) found in natural cannabis. This makes it a lot more harmful.
Vape liquid contaminated with synthetic cannabinoids is often a coloured liquid (red, green, blue, purple or pink). They can be of many different brands or be unlabelled. They are more likely to be a liquid added to a refillable vape rather than a disposable device.
Synthetic cannabinoids can cause your mood and perception to change, leading many users to become extremely confused or paranoid. Some become violent or self-harm while intoxicated. Other reactions include hallucinations, panic attacks, psychotic episodes, and death. Because synthetic cannabinoids are much stronger than natural cannabis, it is easier to experience their unpleasant and harmful effects.
Some more effects include:
Anxiety attacks.
Paranoia and delusions.
Seizures.
Confusion.
Violent behaviour.
Memory impairment.
Suicidal thoughts.
Poor coordination.
Insomnia and extreme fatigue.
Rapid heart rate.
High blood pressure.
Risk of death.
Kidney problems.
Nausea and/or vomiting.
Diarrhoea.
Mixing synthetic cannabinoids and alcohol can be very dangerous and lead to a greater risk of death from overdose or alcohol poisoning.
Young people and adults using vapes of unknown origin may be unaware they contain controlled or high-risk substances.
We encourage all services engaging with individuals who vape to:
Discuss the risks of using unregulated or informal vape products.
Promote sticking to legal, labelled nicotine vapes purchased from reputable retailers, when being used as a stop smoking aid.
Encourage individuals to avoid sharing devices, as contents may differ even when packaging appears similar.
Highlight that synthetic cannabinoids (“spice”) are not always detectable by sight, smell or taste, so users may be unaware of exposure.
If a young person collapses or becomes unresponsive following use of a vape:
Seek urgent medical help if in custody or call an ambulance if in the community.
Check breathing and ensure the airway is clear.
Use the recovery position if they are unconscious but breathing.
Stay with them.
Notify staff/paramedics of the vapes/bottles used.
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.
