Law and everyday life · Switzerland
Driving with a cannabis prescription in Switzerland
Zero tolerance — with an explicit exception for patients.
Art. 2 Abs. 2 VRV treats inability to drive as proven on the mere detection of THC. Art. 2 Abs. 2ter VRV exempts anyone who can show that they are taking the substance as medically prescribed. The detection limit is 1.5 µg/L (Art. 34 lit. a VSKV-ASTRA); that does not replace an assessment of fitness to drive in the individual case.
The norm in its own words
„Für Personen, die nachweisen können, dass sie eine oder mehrere der in Absatz 2 aufgeführten Substanzen gemäss ärztlicher Verschreibung einnehmen, gilt Fahrunfähigkeit nicht bereits beim Nachweis einer Substanz nach Absatz 2 als erwiesen.“
“For persons who can show that they are taking one or more of the substances listed in paragraph 2 in accordance with a medical prescription, inability to drive is not deemed proven merely because a substance under paragraph 2 has been detected.” (Our working translation of the German text quoted above; the German wording governs.)
Two words carry the whole rule: can show. Without that evidence, paragraph 2 applies, and it treats inability to drive as proven on the detection of THC alone. So carry the prescription or the pharmacy label; a doctor's confirmation of the ongoing therapy in your wallet is the cheapest insurance available here.
The exception does not dispense with fitness to drive in the individual case: anyone who drives while actually impaired remains liable. And it says nothing about the administrative procedure — fitness to drive is assessed by the cantonal authorities under their own rules.
Why almost nobody writes this up
The Swiss search results on this subject belong to platforms selling video consultations. A rule that mostly means effort for the patient — carrying evidence, keeping documentation — sits badly in a sales funnel. That is why it is here: it is the rule that costs the most to be unaware of.
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What to have with you and what to say at a roadside check is set out in the section At a police check.
This is not legal advice. If criminal or administrative proceedings are under way, a lawyer specialising in road traffic law and — on the question of fitness to drive — your canton's traffic medicine unit are the right addresses. For disputes with the health insurer there are also the Ombudsstelle Krankenversicherung and the Patientenstelle of your canton.