Even in states with legal cannabis, there is still not a universally agreed-upon method to determining how long cannabis stays in your system, or can be detected on a drug test.
This is simply because there are a lot of factors to keep in mind. Frequency, amount, and constituent concentration (how much CBD vs. THC from a given plant) can all greatly affect the rate of cannabis concentration in your body. Testing for specific cannabis concentration is tricky because marijuana constituents such as THC are what’s known as “fat soluble”. In other words, marijuana is broken down into constituents that are then sent to the BBB via the liver. This is the same process your body uses to break down alcohol into individual constituents, the difference being that cannabis constituents are stored in fat rather than the blood stream or remaining in the liver like alcohol.
This makes cannabis concentration difficult to test. Obviously, fat cells are everywhere in the body. So once the cannabis constituents get into the blood stream, they can then be stored anywhere in the body that contains fat cells. Most urine drug tests test for one of two cannabinoid compounds occurring in cannabis. The first, THC, and the second is a metabolized version of THC known as THC-COOH. Even though a person has cannabis in their system, doesn’t mean that particular individual is ‘high.’ They may not have even consumed cannabis that day.
THC-COOH concentrations in rare users can be detected on a urinalysis up to 48 hours after ingestion, on average. THC-COOH concentrations in frequent users can be detected for far longer, up to 30 days after ingestion on average. However, we still have yet to find a concentration equation since it varies from person to person based on their individual characteristics. The high demand from law enforcement though, might make the process move a little faster!