Cannabis

General 6: What happens in the kidneys?

The breakdown products (metabolites) of the THC arrive at the kidneys’ filter elements, the nephrons. They flow with the blood fluid, or plasma, through the filters (1) and become part of the primary urine. The largest part of this liquid is then returned to the bloodstream (2). The rest constitutes the final urine (3) and it will leave the body via the bladder.

THC breakdown products have different elimination half-lives. The concentrations of some metabolites are halved within 30 hours. That means they are detectable in the urine for quite some time after cannabis use. In addition, the THC that is stored in fatty tissues continues to be slowly released into the bloodstream and processed in the liver.

As a result, cannabis remains detectable in the body for a considerable period after the last use. This ranges from 1 to 3 days for occasional use to 2 to 3 weeks for intensive use.