Synthetic cannabinoids (spice, K2, Buddha Blue)

Where the substance comes from

Synthetic cannabinoids are laboratory chemicals that imitate the effects of tetrahydrocannabinol, the active principle of cannabis, but far more powerfully. They bind to the same brain receptors and activate them much more completely, which explains how abrupt the presentations are. They are commonly sold as spice, K2, Buddha Blue or, in France, PTC. The molecules change constantly: as soon as one is scheduled as a controlled drug, a variant appears, which makes any list impossible to keep current and any label worthless.

Production is industrial and distant; the powder is then dissolved locally into e-liquids, sprayed onto inert plant material to imitate herbal cannabis, or worked into gummies and sweets. Concentration varies from one bottle to the next and within a single bottle: two puffs of the same product do not deliver the same dose.

A little history

These molecules come not from trafficking but from research. In the 1980s and 1990s pharmaceutical and university laboratories made dozens of compounds able to activate cannabis receptors, to understand the endocannabinoid system and look for painkillers: Raphael Mechoulam's HU-210 in 1988, Pfizer's CP series, and above all the JWH series of the American chemist John W. Huffman, whose JWH-018, synthesised in the mid-1990s, would be copied by traffickers.

Around 2004 herbal mixtures sold as incense "not for human consumption" appeared in Europe under the name Spice. It took until December 2008 for German laboratories to identify what they contained: synthetic cannabinoids sprayed onto inert plants. The bans that followed, molecule by molecule, set off a race: every banned product was replaced by a legal cousin, and the European early-warning system has catalogued more than two hundred of these substances.

The legal response changed in nature in the 2010s: classification by chemical family rather than by molecule, and the British act of 2016 banning any psychoactive substance not exempted. The waves of severe poisonings — MDMB-CHMICA in Europe in 2014-2016, epidemics in British prisons — showed that these products no longer have much to do with the cannabis whose name they borrow.

The forms it takes

• E-liquids for vaping devices, colourless and odourless, sometimes presented as legal and sold as “CBD”. This is now the dominant form among teenagers and the most deceptive: nothing in appearance or smell distinguishes the product from an ordinary e-liquid.
• Impregnated plant material, sold as herbal cannabis or mixed into it.
• Gummies, sweets, capsules, with the same delayed onset as cannabis edibles and therefore the same risk of redosing.
• Resins and powders sold under the trade names above.

The figures behind the alert

Between the start of 2025 and 30 April 2026, the French medicines agency recorded around 500 reports through the network of addiction-monitoring centres. More than 70 % concerned people aged 13 to 18, male. 71 % of cases were severe, with two deaths — one from repeated seizures, one by suicide. Where the vaped e-liquid or a biological sample was analysed, in close to one case in five, one or more scheduled synthetic cannabinoids were identified.

Immediate unwanted effects

Presentations are heterogeneous and may combine:

• Neurological: agitation, confusion, seizures, impaired consciousness up to coma.
• Psychiatric: hallucinations, panic attack, suicidal ideation, withdrawal signs.
• Cardiovascular: tachycardia and chest pain, but also bradycardia, arrhythmia or circulatory collapse.
• Digestive: nausea, vomiting.

In the most severe forms, acute multi-organ decompensation is seen, combining neurological, cardiovascular and metabolic involvement — severe acidosis, high lactate.

Because the symptoms are non-specific and clinicians are not widely alert to the problem, the phenomenon is under-detected: a teenager brought in with a seizure or an acute psychotic episode is not spontaneously asked what they have been vaping.

What to do

• Any sign of severity — seizures, impaired consciousness, extreme agitation, respiratory distress, chest pain — means the emergency department, and so does any worrying presentation even without a major sign.
• Say what was consumed, including if it was sold as legal. Synthetic cannabinoids are not looked for in routine toxicology, and some recent molecules escape hospital methods altogether: without the information the diagnosis is missed.
• Keep the suspect product — bottle, cartridge, herb, resin, gummies — without handling or discarding it, where that can be done safely. It can be analysed.
• Ask for advice from the regional addiction-monitoring centre or the poisons centre.

Getting the product analysed

Where a product connected with the case is available, its collection and analysis can be offered through a national identification scheme for toxic substances. Analysis is free and anonymous, carried out by partner laboratories able to identify many synthetic cannabinoids, including emerging compounds that routine biological testing does not detect. The results serve three purposes: understanding and treating the case, rapidly identifying new substances in circulation, and assessing the health risk. In France professionals contact their regional coordination or the national one at sintes@ofdt.fr.

Reporting a case

Every suspected or confirmed case should be reported without delay. In France that is done through the adverse health event portal, signalement.social-sante.gouv.fr:

1. Open the portal, click “report an adverse event”, choose the health professional route.
2. Enter the section on adverse health effects suspected to be linked to consumer products.
3. Choose the right form: addiction monitoring where substance use is suspected; vaping and lung disease for severe pneumonitis in a vaper; toxicovigilance for other vaping-related events.
4. Record the age and sex of the person exposed, the circumstances (route: e-liquid, smoked, other), history, the signs observed and their severity, the treatment and the outcome; then anything known about the product — street name, photographs.
5. Submit: the report goes straight to the regional addiction centre, the regional health agency or the poisons centre depending on the form.

These reports are what make it possible to characterise the phenomenon, assess the risk and adapt prevention. Other countries run equivalent early-warning systems; the country pages give the route to use.

Why the effect is stronger in adolescents

Distribution happens very largely in and around schools, by exchange or resale between pupils, which explains why minors dominate the reports. Three things make this worse at that age. The product is presented as legal, so perceived as harmless. It is invisible: a vaping device gives off no smell and looks like anyone else's. And the adolescent brain, still maturing, reacts more strongly at the same dose in a lighter body. A teenager can therefore absorb in two puffs a dose that would severely poison an adult.

For a parent or a teacher the warning sign is not smell — there is none — but behaviour: sudden panic, confusion, unexplained agitation, collapse or repeated vomiting in a teenager who vapes. The useful reflex is to collect the vaping equipment and hand it to the clinicians.