Yes, when you smoke or eat cannabis, your body breaks down the drug into molecules known as “metabolites”, which are stored in your body’s fat cells. These metabolites leave your body over a period of weeks and months, through natural processes such as sweat, saliva, and urine. The exact time required depends on the amount and frequency of cannabis used, as well as the body mass and metabolism of the consumer.
Some anti-drug pamphlets suggest that these metabolites can “leak out” days later, causing a delayed “high”, but this is not true. The chemical “Delta-9-THC” which causes the “high” lasts only a few hours, and is broken down into the inert metabolites “11-hydroxy-tetrahydrocannabinol” and “11-nor-9-carboxy-delta-9-tetrahydrocannabinol”, which are the ones that remain in fat cells.
This does mean, however, that you can still fail a urine test months after smoking your last joint.