Culture & Nightlife | Nightlife column

Crisis on Zurich’s weed market

There is a sense of anxiety among consumers in Zurich: the weed sold on the illegal market increasingly contains synthetic additives. These substances are suspected of having led to fatal overdoses in Europe. What does this now mean for consumers and what conclusions should politicians draw?

Cannabis is by far the most widely consumed illegal drug in Switzerland. According to national monitoring, around 30 per cent of Swiss adults have consumed cannabis at least once in their life.

2019 saw the emergence of a new phenomenon in the cannabis market, both in Zurich and beyond. Cannabis laced with synthetic cannabinoids is increasingly being sold. According to, in most cases this is laced pot. However, synthetic cannabinoids have also been detected in analyses of hashish. Lacing with synthetic cannabinoids massively increases the risk associated with cannabis consumption. This is understandably giving rise to anxiety among consumers. While in the past cannabis products differed in strength, they were never laced.


Very few cannaboids are banned.

Cannabis is not just a stimulant and an intoxicant, it is also a medicinal drug. So it is hardly surprising that decades of research have been conducted into synthetic cannabinoids – artificially produced substances with an effect similar to herbal cannabis. The first synthetic cannabinoids were developed in the 1960s, shortly after sequencing of the chemical structure of THC, the active component of cannabis. Originally used in medical research, since around 2000, synthetic cannabinoids have also been increasingly used as recreational drugs.


Synthetic cannabinoids first appeared in Switzerland in 2008, in the form of a ‘herbal mixture’ sold under the name of Spice. Consumers reported effects similar to those produced by cannabis. Analyses of the product finally revealed that the effect was not down to the herbs contained in Spice but to the synthetic cannabinoids they had been treated with. In 2009, the first synthetic cannabinoids were classed as narcotics. However, given the vast diversity of synthetic cannabinoids, very few are currently illegal. Legislation has the power to ban only a specific molecule but not entire groups. At the time, demand for herbal mixtures was relatively low in Switzerland, even when these were still sold legally in head shops. This was mainly attributable to the favourable price/performance ratio on the Swiss cannabis market as well as the absence of supply bottlenecks. There was no reason for consumers to consider experimenting.

Our drugs policy is failing.


The situation today is different and synthetic cannabinoids are no longer sold as herbal mixtures – legal cannabis substitutes – but are instead sprayed onto cannabis flowers and mixed into hashish. These laced products are then sold on the black market as normal cannabis or hash containing THC. Analyses conducted in Switzerland show that these products are based on CBD cannabis laced with synthetic cannabinoids. There is probably no single reason for the increasing prevalence of this phenomenon. One hypothesis is that it bypasses the law, as cultivation of CBD cannabis and most synthetic cannabinoids are legal in Switzerland. Another possible explanation is the collapse in prices on the CBD market in recent years, driving efforts to salvage investments with laced CBD cannabis. However, there is potentially also a link to a supply shortage related to Covid-19. Travel restrictions are reducing smuggling capacity. Whatever the main reason may be, the current situation is once again highlighting the failure of our drugs policy.

The effect is far stronger.

Ultimately, consumers are suffering once again. The risk associated with consumption has increased. Not just because the undeclared additives create a greater risk of unintentional overdose. Unlike natural cannabinoids, there are practically no facts available on the risks of consuming synthetic cannabinoids.


Users report a far stronger effect than usual. Side effects include palpitations, decelerated breathing, confusion, hallucinations, as well as acute psychoses and aggressive behaviour. The strength of the craving experienced is also described as far higher. In Europe and the rest of the world, consumption of synthetic cannabinoids has resulted in the deaths of several dozens of people.


For consumers, this means that they either start growing their own cannabis or having purchased cannabis tested at the Drug Information Centre (DIZ) before consumption. If this is not possible, they should ‘test’ newly purchased cannabis with a small dose on first use. If they experience any unexpected effect within 15 to 20 minutes, they should cease consumption immediately. It is important to mix cannabis products thoroughly before consumption (ideally using a grinder) to avoid a high concentration of possible synthetic cannabinoids on individual parts of a plant. Particular care must be taken with residual material that has fallen off the outer parts of a plant, as this often contains a particularly high concentration of synthetic cannabinoids. Seek immediate medical advice in the event of suspected poisoning by synthetic cannabinoids.

In the interests of all, we must hope that politicians will realise that the current drug policy is simply causing unnecessary suffering. Sticking plasters in the form of controlled access for research purposes will not help. We need a fundamental shift in mindset. By legalising access to cannabis, people’s health should be the future focus of our drugs policy.

The Drug Information Centre (DIZ)
The Drug Information Centre (DIZ) is a service provided by Streetwork, the City of Zurich’s youth advisory service, offering information and counselling as well as onsite drug checking. The DIZ provides information on the effects and dangers of psychoactive substances, as well as on the risks for users based on their own consumption behaviour. Drug checking allows users to have their substances tested to obtain precise details on their composition and dosage, as well as the effects these substances could have on them. The DIZ service is anonymous and free of charge.


Drogeninformationszentrum Zürich (DIZ)
Wasserwerkstrasse 17
8006 Zurich
+44 415 76 46