
Those hoping to test clean for cannabis may have a while to wait. Cannabis compounds can be detected in the urine for as long as one month on average after consumption. This is longer than most other commonly tested substances, like alcohol and cocaine. Here’s why THC can take up to 30 days to clear your system.
How long does cannabis stay in your system?

Cannabis compounds can stay in your system for a significant chunk of time. The most common way to be tested for cannabis is with a urine test.
However, urine tests don’t exactly measure tetrahydrocannabinol (THC). Rather, they measure the concentration of a THC metabolite, called THC-COOH. These metabolites show that the body has broken down THC.
Much to the dismay of many cannabis consumers, these metabolites can be present in urine for up to 30 days post-consumption. In light consumers, this number drops down to just a couple of weeks.
In one 1985 account, THC was found in the bloodstream of a chronic consumer for as long as 77 days after consumption. The study also suggested that on average, most routine cannabis consumers can expect to have the herb clear their urine in 25 days.
A later study confirmed the average number, estimating that it took heavy cannabis consumers around 27 seven days. to test clean in urine. Generally speaking, most cannabis consumers can expect to test clean after about one month of abstinence. Consumers who test positive after 30 days are typically seen as outliers.
However, the average amount of time THC or THC metabolites can be detected depends on the way the compounds are measured. Here’s how long you can expect to wait for different types of tests:
- Blood: 1 to 7 days (14 for heavy consumers)
- Hair: 90 days
- Saliva: 1 to 7 days
- Fat: Several weeks
Why does THC stay in your system for 30 days?

If the above research is any indication, it can take quite a while for THC to be completely cleared from the system. This is because cannabis is stored in fat, which makes it stick around longer in the body. After inhaling or ingesting cannabis, THC is quickly pulled out of the bloodstream and into fatty tissue, like the brain.
If you just smoke a casual joint, it’s not likely that THC will be detectable in urine after one week. However, the compound will take longer to clear out of heavy consumers.
The total length of time THC stays in your system depends on several factors, including:
- Individual metabolism
- Individual body mass index (BMI)
- Amount consumed
- Frequency of consumption
- Potency of the cannabis product
- The type of testing used
Once THC is tucked away in fat cells, the cannabinoid is then re-released as these fat cells are burned for fuel. In fact, two small human studies have shown that blood plasma levels of THC are elevated after exercise.
This means that after you consume THC, trace amounts of the compound continue to release and potentially exert effects for a while after inhaling or ingesting.
Interestingly, one of the studies also found that participants with larger BMIs showed the highest increases in post-exercise THC release.
This may be an added benefit to some, though the THC released by the body is not likely to cause noticeable cognitive changes. Though, exercise is always a great way to boost mood and experience an enjoyable, natural high.
Searching for more information on drug testing? Check out these articles below:
- Does Using Fake Pee Guarantee You’ll Pass A Urine Test?
- Detox: 6 Quickest Ways To Flush THC From Your System
- How To Pass A Blood Test For Cannabis
- How To Pass A Hair Follicle Test
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