How Long can Cannabis Stay in Your System?

Green Dragon Florida does not provide medical advice and makes no medical claims. The information contained in this article is intended solely for educational purposes and is based on external research. Green Dragon Florida does not endorse or assume responsibility for the accuracy of the research presented.

Detecting cannabis in the body can happen through blood, saliva, urine, or hair tests, but the most common is urine analysis. THC, the main active part of marijuana, gets into the body's fat cells and is changed by the liver into other substances, which can be found for different times based on how often someone consumes marijuana. If you only consume occasionally, it usually takes about 3 days to test clean, but for patients who consume a lot, it might take over 30 days. Things like weight, how much you drink, and exercise can affect how fast THC leaves your body.

In Florida, laws now let patients consume medical marijuana, but not everyone accepts it. Since the time of Regan, federal rules have stopped U.S. government workers from using any kind of marijuana. Some states and cities have similar rules, and even some private bosses have them too.

Even though some states say bosses can't treat workers differently just because they consume marijuana (for medical or recreation), Florida isn't one of those states yet. This makes it tricky for the over 700,000 patients who can consume medical marijuana in Florida but work in places where it's not allowed. For these patients, knowing how marijuana works in the body and how tests find it might be more than just something to learn about.

How is cannabis detected in your system?

Detecting marijuana in the body can be done through blood, saliva, urine, and hair tests, but blood tests are not common because THC leaves the blood quickly. In a study, consumers who smoked a joint with low or medium THC levels showed THC in their blood in less than a minute. The THC reached its highest level in less than 10 minutes after smoking and went down fast, usually undetectable within two hours.

But even though THC leaves the blood fast, it doesn't mean it leaves the body fast. Unlike alcohol, which goes away quickly, THC goes into the body's fat and comes out slowly over time. It changes in the liver into other forms called metabolites, which can be found in saliva, urine, poop, and hair. Urine tests are the most common and look for a major THC metabolite called THC-COOH, measured in nanograms per milliliter (ng/ml).

For regular marijuana consumers, THC-COOH levels in urine usually peak one to four days after using and can be as high as 300 ng/ml. After stopping, levels drop to about 50 ng/ml in three to five days but can still be found for up to a month. For patients who only consumer once in a while, THC-COOH levels drop to 10 ng/ml or less within four to five days of stopping.

Cannabis Testing Methods

Urinalysis tests for THC breakdown products usually happen in two steps. First, a simple and cheap test called enzyme immunoassay checks for any marijuana signs. If it finds something, a second test, called gas chromatography/mass spectrometry (GC/MS), is done to make sure the first result is right. Studies show the first test is accurate about 95 to 97% of the time, while the second one is almost always right.

The levels needed to show a positive result can vary, but the most common ones used by the U.S. government and others are 50 ng/ml or more for the first test and 15 ng/ml or more for the second one. Interestingly, the NCAA recently made it easier for student athletes, saying they won't get in trouble unless they have more than 150 ng/ml in their system.

How Long Does it Take for a Cannabis Test to Test Negative?

Beyond the science, most medical marijuana patients want to know how long it takes to test clean in a urine test. Different things can affect it, but there are some general timelines to keep in mind. According to the Mayo Clinic:

- If you consume marijuana occasionally (up to three times a week), you'll probably test clean within 3 days.

- For moderate medical marijuana consumers (about four times a week), it might take 5 to 7 days.

- If you consume medical marijuana every day, it could be 10 to 15 days.

- But for heavy consuming patients (multiple times a day), it might take more than 30 days.

A paper from the National Drug Court Institute gives even more details:

- If the test looks for 50 ng/ml, it's unlikely for a heavy consumer to test positive after 10 days.

- If it looks for 20 ng/ml, it's rare for a heavy consumer to test positive after 21 days.

- If you only consume sometimes, it's unusual to test positive after 3 to 4 days.

- And with a cutoff of 20 ng/ml, a one-time consumption shouldn't show up after 7 days.

Variables that can Influence Positive Test Rates

Studies have found a few things that can affect how fast your body gets rid of THC-COOH. One big factor is how long and how much medical marijuana you've consumer. Patients with a higher body mass index (BMI) might keep THC metabolites longer because they're stored in fat. A study in the Journal of Analytical Toxicology found a link between BMI and how long THC stays in urine. They also said:

- THC can come out of fat into the blood at different rates, maybe because of how active you are, what you eat, or other things we don't know yet. This can change how much THC shows up in urine.

Drinking enough water can help get rid of THC metabolites in urine, but drinking too much won't speed it up. Some studies show that drinking more water than your body needs doesn't help get rid of THC any faster.

Exercise might help release THC from fat cells, but it might not make a big difference. A study in Drug and Alcohol Dependence found:

- Exercise raised THC levels in the blood a bit, especially in people with a higher BMI.

- It didn't matter if people had eaten or not before exercising.

But another study with six regular marijuana patients found that exercise and not eating didn't change THC levels in blood or urine much. They said:

- Even though THC levels went up a little during exercise, it didn't last long.

- Fasting and exercise didn't make a big difference in THC levels.

Because lots of things can affect how long it takes to test clean for THC, it's hard to say exactly when it will happen. But based on what we know now, medical marijuana patients can guess when they might test clean based on how much they use and other things about them.

**Disclaimer:**

Green Dragon Florida does not provide medical advice and makes no medical claims. The information contained in this article is intended solely for educational purposes and is based on external research. Green Dragon Florida does not endorse or assume responsibility for the accuracy of the research presented. For a comprehensive understanding, please read this article.