In Brabant, legal grown hashish is sold with extremely high amounts of tetrahydrocannabinol (THC), the active substance in hashish, so you can experience a high. It concerns the normal average amount twice. Omroep Brabant discovered this during a sample. The find is special, because the goal of legal hash is a ‘safer’ alternative to illegal hashish from the government. The Trimbos Institute is shocked by the find and is worried.
For recordings of the Omroep Brabant podcast Via the front door We bought five legal and illegal hash species at three coffee shops in Breda and Tilburg to have this blind tested by two seasoned blowers. The packaging of legal hashish says exactly how much THC is in it.
When buying the hash, we came across one kind that contained twice as much THC as average and that is worrying, according to the Trimbos Institute. When purchasing, the seller did not give a warning or explanation about the strength of the hashish.
Twice as much THC
Since 2000, the Trimbos Institute has been investigating how much THC is on average in illegal weed and hashish. In 2024, Dutch, illegal hashish contained an average of 26 percent THC and imported, illegal hash 22 percent. The legal hash that we came across contained 60 percent THC, so that is twice as much as average.
“There are more and more researchers who warn about the dangers of this kind of super strong cannabis products,” says Pieter Oomen, researcher at the Trimbos Institute. The Knowledge Institute for addiction care, among other things, comes across Hashprodcuten with high THC values, but according to Oomen, those are outliers. “The average THC levels of hashes are normally between twenty and thirty percent. So this hashish is soon twice as strong. Even a seasoned Blower notes that difference immediately.”
Chance of harmful effects greater
Within the weed experiment (see box) there is no limit to the amount of THC that may be in a product. “The legal growers determine the strength themselves. But these kinds of super strong products are certainly a concern.”
Weed experiment in short
Since the 1970s we have had a tolerance policy in the Netherlands. You can buy and smoke weed, but not grow or transport weed. The government wants to change this with the weed experiment. Over the next four years, only legal cannabis can be sold in ten municipalities in the Netherlands in the Netherlands. It may be grown by ten designated growers.
Since April 7, coffee shops in the municipalities that participate in the weed experiment only sell legally grown weed. Due to a limited supply stock, an exception has been made for Hash, but from 1 September only legal, grown in the Netherlands (Nederhasj), may be sold.
The aim of the weed experiment is for the central government to investigate the effect of a legal cannabis market on public health, crime and safety in the Netherlands. Through quality controls on legal cannabis, there is more certainty for consumers on a ‘clean’ and ‘safe’ product.
According to the Trimbos Institute, a high THC content can increase the risk of harmful effects. Think of memory problems, anxiety and a greater chance of addiction. “With heavier products, that damage is also reflected faster, especially with frequent use,” says Oomen. “It is important to state that other cannabis species with lower THC values also cause the harmful effects, but you have to take more of it.”
According to Oomen, most consumers do not want products with very high THC values, because the effect is too intense. In any case, the addiction institute keeps a close eye on it. But as long as there are no legal limits to the strength of cannabis products, according to him, the designated growers can legally offer the powerful products.
Keep thinking
We asked the legal grower of the hash species with the high THC content, earthy, why they breed such a strong species of hash. “We meet the demand from the market. On the illegal market you can also get hashish with similar percentages of THC and this competition we have entered into,” says a spokesperson. They indicate that the opinions about the hashish with high THC levels are distributed internally. “It makes us think again.”
In addition, they place part of the responsibility with the hash consumer. “We believe that people must always keep thinking about what you have bought and how much you use of it at a time. This should not be arranged by the grower nor the government.”
Should there be a THC limit?
The government has set up the weed experiment. The Trimbos Institute is involved in the monitoring of the weed experiment. According to Oomen, reports show that the Advisory Committee did not think it was necessary in advance to take a THC limit in the experiment, because such high THC values were not expected. “The THC values on the market were not at all that high at the time, those were rarities.”
Should such a THC limit still have to come? Oomen cannot make any statements about that. “This kind of developments are worrying and we try to put attention on it, but we mainly have a role as researchers about the progress of the effects of the experiment. So giving policy advice is not up to us at this stage.”
Whether he expects a THC limit after evaluation of the weed experiment, he says: “The policy will of course be made in The Hague. It could well be that at the end of this experiment will roll out that such a limit is desirable.”
Hein Schafrat, spokesperson and board member of Platform Cannabis companies Nederland (PCN), has been around for a long time in the cannabis world and is not upset. “It is of course just what a consumer wants. One would rather drink a beer and the other a whiskey, there are also blowers with a preference for stronger hashish.”
He thinks you should be warned about it. “It is up to the coffee shop to properly inform the customer that something is a stronger species of hash and that you have to use less of it, for the same effect. So that you do not receive this information is not good, although of course there is also a responsibility with the customer.”
Curious how seasoned blowers experience the legal and illegal hashish? Then watch the video below:
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Do you want to know everything about the weed experiment? In the podcast series ‘Via the front door’ journalists from Omroep Brabant dive into the world of weed. Listen below all episodes of the podcast series. Do you have questions or comments about the weed experiment? Then mail the Research editor.
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