How Long Does Marijuana Remain In Your System?

The Conventional Advice Of At Least 30 Days, Is Not That Straight Forward

There are many different kinds of drug tests available, with various sensitivity levels and time periods that they will detect marijuana in your body. The amount of marijuana you use as well as your unique biology, makes the answer to the question “how long does marijuana stay in your system” more complicated.

“Unfortunately, there is no short or easy answer to that question. The cannabinoids are fat-soluble and are stored in body fat and released from there over time, so whether they show up on drug testing (which I assume is the actual question) depends on many factors, including how much cannabis has been used over what period of time, how much body fat someone has, exercise patterns, diet and others.”

To measure THC in the body, drug screenings actually measure carboxy-THC, a breakdown metabolite of marijuana. And that process is also affected by a number of factors. Says Paul Armentano –  deputy director of the National Organization for the Reform of Marijuana Laws “The body’s excretion of carboxy-THC is influenced by the subject’s metabolic rate, percentage of body fat, and is also likely moderated by stress levels and diet.”

Drug Tests

40-50 million drug tests are conducted by employers each year. These test material including urine, hair, blood, saliva, breath, sweat, and even fingernails. When cannabis is consumed, THC levels temporarily rise in the body. These are detectable by blood tests from several hours up to a day after a single usage.
THC, CBD, and their metabolites, are lipid-soluble and group together in fat reserves throughout the body. These molecules are then slowly released over a period of time. Hair tests tend to have the longest detection window. They are capable of registering the levels of a non-psychoactive THC metabolite up to 90 days after cessation.

Urine tests are the sole test recommended by the Substance Abuse and Mental Health Services Administration (SAMHSA). The most common level for most urine tests to be considered positive is 50 ng/mL. However, cutoffs can be as low as 15ng/mL and as high as 100ng/mL.  Testing is usually a two-step process. The first step is a qualitative yes/no with a typical cutoff of 50 nanograms per milliliter. If it tests positive, it will be sent off for confirmation with a more sensitive assessment that uses a 15 nanograms per milliliter cutoff.

How Long Does Cannabis Stay in Your System?

Each of us has a unique metabolism that processes cannabis at a different rate, further complicating coming up with concrete time line for drug testing . Even amongst people of the same gender and age, individual lifestyle choices such as levels of exercise and eating habits may also affect the amount of time required to pass a drug test (those with higher levels of fat content store cannabinoids more readily than leaner body types).

Some individuals fluctuate between positive and negative tests over a period of time.

“A lot of people call us and say the person was negative and now they are positive, and they say they haven’t used, But if a person becomes dehydrated it concentrates the urine and when they exercise it breaks down fat cells and releases THC, So you will actually see that over time they will go up and down between positive and negative.In a single acute use for a fixed dose we might see a range of variability on the order of days,” he says. “So someone might be clean the next day and others might be positive for seven days. And if you are talking about frequent repeated use the variability just gets bigger. I have had people who smoked cannabis all day every day be clean in a week and a half, and others be dirty for two months.”

Bottom Line

There is no way to tell how long cannabis will stay in your body, there is too many variables to make a rule of thumb for Drug testing detection.