THC Breakdown Calculator
How long can THC be detected?
How long THC stays detectable in your body really depends on the testing method, how often you use it, and your individual factors. If you use cannabis just once, it usually only shows up in your blood for a few hours, but can be found in urine for several days. If you use it regularly or daily, the detection window gets much longer, since THC stores in your fat tissue and slowly moves back into your blood.
Just five quick questions will give you a personalized estimate with the exact date when THC is likely no longer detectable — and you can export it as a calendar reminder.
Question 1 of 5
How often do you use it?
Which test methods detect THC?
Four test methods are most commonly used in practice — each with different detection times and areas of application.
Blood test
A blood test detects active THC as well as its main metabolite 11-OH-THC. These values are relevant for assessing fitness to drive. Active THC indicates recent use — usually only a few hours after a single intake, and up to several days with regular use.
Urine test
A urine test detects the breakdown product THC-COOH. Since THC-COOH is excreted much more slowly than active THC, the urine test has the longest detection time among standard methods — up to eight weeks with very frequent use. Urine rapid tests are the most common method for routine workplace checks.
Saliva test
The saliva test detects active THC through the oral mucosa and is mainly suitable for identifying very recent use. The detection time is a few hours for single use, and up to four days with regular use. Police traffic checks often use saliva tests because they are quick and non-invasive.
Hair analysis
A hair analysis can detect cannabis use retrospectively for about 90 days per centimeter of hair length. Since this test covers very long periods, it is usually only used for official investigations such as the medical-psychological assessment (MPU).
Which factors influence THC detection time?
THC, the psychoactive component of cannabis, is broken down in the body at different rates. Four main factors determine individual detection time:
Frequency of use
With single use, THC disappears from the blood relatively quickly. With regular or daily use, THC accumulates in fatty tissue, which significantly extends the detection time.
Route of intake
With inhalation, THC reaches the bloodstream within minutes and is metabolized relatively quickly. With oral intake, first-pass metabolism occurs in the liver — the metabolite THC-COOH can therefore be detected for a longer period.
Body weight and body fat percentage
THC is fat-soluble and accumulates in fatty tissue. People with a higher body fat percentage tend to have longer detection times, as THC returns more slowly from fat stores to the blood and is then metabolized.
Metabolism and individual factors
Metabolic rate, fluid intake, physical activity, and liver health influence how quickly THC is excreted. These individual factors cannot be reflected by a calculator — the values should always be understood as estimates.
Detection times at a glance
THC limits for driving in Switzerland
Switzerland has a practical zero-tolerance policy: From a THC level of 1.5 nanograms per milliliter of blood (1.5 ng/ml), fitness to drive is considered no longer given. This limit is much stricter than in many neighboring countries. In Germany, the limit has been 3.5 ng/ml since 2024.
If you regularly use cannabis and drive, you should allow for generous waiting periods — individual breakdown times can vary significantly from the averages. In Switzerland, repeated violations can lead to license suspension, high fines, and a traffic medicine assessment.
How can you speed up THC breakdown?
THC is fat-soluble and is metabolized by the liver, then excreted via stool and urine. You can't really speed up the natural breakdown — your metabolism works at its own pace. What can help:
Helpful
Drinking enough fluids — two to three liters of water per day, regular physical activity like endurance sports, a diet rich in fiber, enough sleep, and avoiding further use all support the natural breakdown.
Ineffective or even counterproductive
Detox drinks and detox programs from the internet are not scientifically proven. Some detox products can even be seen as an attempt to manipulate results in modern tests. Sauna sessions and excessive exercise right before a test can actually raise your levels in the short term, since THC is released from fat tissue into the blood.
Swiss hemp products without THC
Green Passion offers a wide range of legal Swiss hemp products. Product categories at a glance:
Frequently asked questions
Sources and further information
- German Society for Traffic Medicine (DGVM): Stell
