Ask in an Amsterdam coffeeshop whether the weed was lab-tested and you get a shrug. Ask 100 kilometres south in Breda and the answer is printed on the packet. The Netherlands now runs three cannabis safety systems at once. Here is who is responsible for each, and how to tell which one you are standing in.
Three tracks, one small country
The coffeeshop track. Since the 1970s, selling small amounts of cannabis in a licensed coffeeshop has been tolerated, not legal. The rules are about behaviour, not the product: no advertising, no hard drugs, no nuisance, no minors, no more than 5 grams per person per day, no more than 500 grams in stock, and in many cities residents only. The mayor, the public prosecutor and the police set local policy and enforce it. Nothing in those rules requires the cannabis to be tested, because until recently nobody was allowed to grow it for the shop in the first place. That is the famous "back door" problem.
The experiment. Since 7 April 2025, every coffeeshop in ten municipalities (Almere, Arnhem, Breda, Groningen, Heerlen, Maastricht, Nijmegen, Tilburg, Voorne aan Zee and Zaanstad) may sell only cannabis grown by ten licensed producers: lab-tested, sealed, labelled and tracked from greenhouse to counter. It runs for four years, with an evaluation due in 2028.
The medical track. The Office of Medicinal Cannabis (BMC), part of the health ministry, is the only legal supplier of cannabis to pharmacies. Five standardized flower products, prescription only, each batch released against a published certificate.
Who checks that it is safe
Inside the experiment, the job is deliberately split so no single body holds the whole chain:
Licensed growers (a maximum of ten) cultivate, test and package every batch.
The NVWA, the Dutch food and consumer product safety authority, supervises the growers on quality, packaging and the advertising ban. It takes its own samples at inspections and sends them to the Wageningen Food Safety Research lab. A batch that fails is destroyed.
The Justice and Security Inspectorate (Inspectie JenV) polices the closed chain: grower registration, security, transport, waste, and the track-and-trace records at each coffeeshop. Against coffeeshops it cannot enforce: it reports, and the mayor acts. Growers it can sanction directly.
Mayors supervise the coffeeshops; the police and prosecutor handle anything criminal.
Independent researchers (Trimbos, Breuer&Intraval and RAND Europe) evaluate the whole thing for the WODC research centre, on behalf of the justice and health ministries. In its first year the Inspectorate ran 46 grower inspections, logged 42 violations, mostly registration errors and security gaps, and took 32 enforcement measures, mostly warnings; four growers actually paid penalties of 1,000 to 20,000 euros.
What "tested" actually means
A batch is one variety from one harvest. Each batch is sampled three times: one for the lab the grower commissions, one for the NVWA, one held back for a counter-analysis. The labs must hold an Opium Act exemption. The panel covers:
Heavy metals: lead, mercury, cadmium and arsenic.
Micro-organisms: bacteria, moulds and yeasts.
Aflatoxins, the mould toxins.
Pesticides: only pesticides on the NVWA's exempted list may be used, and the NVWA checks leaf samples several times a year.
THC and CBD, measured so the label can state them.
Two things you might expect are missing. There is no maximum THC: any strength is allowed. And terpenes are not part of the required tests.
What does untested look like? In a baseline study published in January 2025, researchers had bought 105 samples from ordinary coffeeshops. About a third carried pesticide traces, one in five weed samples exceeded the microbiological limits, and one hash sample was over the lead limit. Trimbos judged the levels posed no extra risk to otherwise healthy people, but that is the baseline the experiment was built to replace.
The part you can check yourself: the sealed 5-gram pack
In an experiment city, the packet is the proof. It must be sealed, hold at most 5 grams, be transparent or a plain solid colour with no print or logos, and carry a label covering at least 30% of the pack: variety, THC and CBD percentages, net weight, a unique identification code, harvest and packaging dates, the producer's contact details, the red THC symbol, warning symbols, "buiten bereik van kinderen" (keep out of reach of children) and a QR code to a standard leaflet. A QR code to the lab results is allowed but optional. The shop may keep a small open sample for you to look at, but can only sell you the sealed unit.
In Amsterdam, Rotterdam, The Hague, or any of the roughly 90 other municipalities with coffeeshops, there is no required seal, label or test. The bag is whatever the shop put in it.
The twist: Amsterdam was proposed, and Parliament said no
Amsterdam has 167 coffeeshops, close to 30% of the country's 563. The cabinet proposed adding a single Amsterdam district, Amsterdam-Oost, as an eleventh municipality. On 5 March 2024 the Tweede Kamer voted the bill down. So the country's most visited city stays on untested supply, while Breda, Tilburg and Maastricht sell sealed, lab-checked packs.
The medical track, meanwhile, is quietly unwinding: the state ended its contract with its sole grower on 1 January 2026, is supplying patients from stock, plans to switch to imports in 2027 and, per the latest patient-group update, aims to have a law ending the ministry's monopoly in force by mid-2028.
What it means for you
In one of the ten experiment cities: buy only the sealed, labelled pack, read the THC and CBD figures, scan the QR, and know that the shop must be able to trace it back to a licensed grower.
Anywhere else, including Amsterdam: assume it is untested. No coffeeshop outside the experiment is required to have a lab report. Start low. The Trimbos institute's Red Alert app warns about dangerous batches, and note that the Dutch drug-checking service (DIMS) does not test cannabis.
Medical patients: every pharmacy product has a batch release certificate you can look up on the BMC website.
Questions people ask
Is cannabis legal in the Netherlands? No. Selling it in a coffeeshop is tolerated, not legal, and the prosecution service's policy is not to prosecute possession of up to 5 grams, though it remains an offence. Even in the ten experiment cities the product is regulated under a temporary experiment law, but cannabis itself remains illegal under the Opium Act.
Is Amsterdam coffeeshop weed lab-tested? No. Amsterdam is not part of the closed-chain experiment. Parliament rejected adding the Amsterdam-Oost district in March 2024, so no testing requirement applies to the city's 167 coffeeshops.
Which Dutch cities sell lab-tested cannabis? Almere, Arnhem, Breda, Groningen, Heerlen, Maastricht, Nijmegen, Tilburg, Voorne aan Zee and Zaanstad. Since 7 April 2025 those coffeeshops may sell only experiment cannabis; enforcement on leftover non-chain hash began 1 September 2025.
Want to see the whole chain, from licensed grower to sealed pack, step by step? Play the interactive walkthrough at weed-central.com/learn/coa/netherlands, and compare it with how other countries and US states do it at weed-central.com/learn/coa.
This article is general information, not legal or medical advice. Dutch cannabis rules differ by municipality and can change; verify the current requirements before relying on any detail.