A customer once told us: "I only take flower, not oil, so I'm sure to have zero THC." It's exactly the opposite of reality. Flower is the form of CBD LEAST likely to be zero THC, and smoking is the method that gets that THC into the body most directly.
Flower is always "full spectrum" by nature
An oil can be made from 99% pure CBD isolate, with no trace of THC. A flower is a raw product: it's the whole plant, with all its cannabinoids, THC included. In Switzerland, the law allows up to 1% THC in a CBD product, and a legal flower generally contains an amount of THC close to that limit – never zero. The myth of "zero THC because it's flower" comes from confusing "legal" with "THC-free", two different things.
Why smoking changes everything
Swallowing an oil sends CBD (and the little THC present) through the digestive system and liver before it reaches the blood, a process that filters and dilutes some compounds. Smoking or vaping a flower bypasses this step: combustion releases THC directly into the lungs, then the blood, within seconds. THC concentration in saliva rises almost immediately after smoking a flower, with a detection window that usually lasts four to six hours.
What this means for a roadside check
This is the most concrete point: smoking a CBD flower just before driving is the riskiest situation for a positive saliva test, far more than an oil taken in the morning. And smoking several times a day, several days in a row, makes these traces build up in the body rather than letting them clear between uses.
"Customers who drive regularly, we always point towards an isolate-based oil rather than flower," says Cyril Piaget, founder of Tiny Green. "It's not that we advise against flower as such – it's just not made for that."
The only real "zero THC" option
If the goal really is never to have any trace of THC in your body, flower isn't the right product, whatever its stated content. Oils or capsules made from CBD isolate, with no other cannabinoids, remain the only product category that truly keeps that promise. Everything else – flower, resin, full-spectrum oil – contains a trace of THC, however legal and tiny.
The confusion often comes from the word "legal", taken to mean "risk-free" or "THC-free". A product can fully comply with Swiss law and still contain enough THC to cause problems in a specific context, like driving. Knowing this when you buy your flower avoids quite a few bad surprises. Also read CBD and driving.
