How long does cannabis stay in your blood?
Smoking a joint is a well-known habit in the Netherlands. Yet it is against the rules to participate in traffic under the influence of weed or hashish, and there are also plenty of employers who do not approve of the use of weed by their employees. Cannabis is a soft drug, the use of which can therefore be demonstrated by analyzing blood or urine. Of all drugs, cannabis remains the longest in the body after its use is stopped.
Demonstrability
In short, hashish and weed can still be detected in the body by testing urine for between five days and three weeks. This depends on the frequency of cannabis use. If you smoke weed sporadically, the cannabis will be gone from your body after four or five days. If you smoke a joint every day, this can take much longer, namely five weeks. Of course, this is also different per person, and individual differences such as weight and fat percentage also play a role. Weed can be detected in the blood for one to three weeks with chronic use. This also applies to the active substance in cannabis THC.
Fat
Cannabis, unlike most other drugs, is not water soluble, but fat soluble. As a result, after entering the bloodstream, the cannabis is released into the fatty tissue where it is temporarily stored. The fatty tissue then slowly releases the cannabis back into the blood. This means that the more fatty tissue a person has, the longer it takes for the cannabis to be completely out of the body, as the cannabis is stored in more fat.
half-life
Another reason why it takes a relatively long time for weed and hashish to completely leave your body has to do with the half-life of THC. The half-life is the time it takes for the body to halve the concentration of a certain substance. For THC, the half-life is several days.
Positive test after second-hand smoke of cannabis?
It is very unlikely that you can test positive for cannabis use if you have 'smoked along', without actually lifting yourself from a joint, pipe, bong or vape. There have been studies that concluded that this was possible, but these studies were conducted under highly unrealistic conditions. In reality it doesn't run that fast, so you don't have to worry about this.