Cannabis and Driving — Switzerland's Zero Tolerance
Switzerland enforces zero tolerance for THC while driving. The 1.5 μg/L whole-blood limit is so low that use days ago can still cost your licence. CBD can also trigger tests.
Switzerland: 1.5 μg/L THC in blood = unfit to drive (SVG Art. 55). Licence withdrawal min. 3 months, fine ~CHF 600–2,000, mandatory fitness examination. THC persists 24–72 h in regular users, 6–24 h in occasional users. CBD is legal while driving, but residual THC in CBD products can trigger tests — always check the CoA.
The law — zero tolerance taken literally
Since 2005 Switzerland enforces zero tolerance for cannabis, cocaine, heroin, amphetamine and MDMA (SVG Art. 55 para. 6). For THC: detection threshold at 1.5 μg/L whole blood (VBG Art. 34).
Comparison: Germany 3.5 ng/mL serum since August 2024. Switzerland is markedly stricter.
What happens at a check
Process: suspicion (red eyes, smell, driving) → saliva test → if positive, blood draw. Only blood counts legally.
Positive result (≥1.5 μg/L): warning + fine CHF 600–2,000, licence withdrawal min. 3 months (6–12 months on repeat), mandatory driving-fitness examination.
How long after use are you unfit?
Occasional users: 6–24 h detectable in blood. Regular users (daily): 24–72 h, up to 30 days in extreme cases (slow release from fat stores).
Practical rule: min. 24 h after a session, min. 7 days for daily users. Subjective sober feeling doesn't protect — the blood test does.
CBD and driving — the grey zone
CBD itself is legal for drivers. Problem: many CBD products contain residual THC (up to 1%). Consuming 1–2 g of flower can push you over 1.5 μg/L.
Safe: prefer broad-spectrum or isolate with declared <0.1% THC, check the CoA.
FAQ
What is the THC limit for driving in Switzerland?
1.5 μg/L whole blood. The lowest in Europe — de facto zero tolerance.
How long after use can I drive?
Rule: occasional 24 h, regular 7 days.
What happens with a positive test?
Licence withdrawal min. 3 months, fine CHF 600–2,000, medical-legal examination.
Is CBD tested too?
The test looks for THC. But CBD flower with residual THC can trigger it.
Am I protected with medical cannabis?
No. Even with a prescription, the 1.5 μg/L limit applies. The fine can be dropped, the licence withdrawal cannot.