Overview

As laws change, talking about marijuana use is slowly becoming more common. Some people are assessing its medicinal value, while others are looking for ways to flush it out of their system because of drug testing or a simple desire to get toxins out of their systems.

But what exactly are they flushing out, and how long would it take to happen naturally?

When you smoke or consume marijuana, you can feel profound and immediate effects. But even once those effects are gone, marijuana metabolites remain. This means that chemical remnants of the plant are still present within your body.

These remnants are called cannabinoids. They can be detected in saliva, hair, fingernails, blood, and urine.

Drug tests look for the presence of the cannabinoid tetrahydrocannabinol (THC) and its metabolites. Generally, urine is tested, both because it’s easiest to collect and because THC remains detectable for a longer period of time in urine than elsewhere.

The main metabolite these drug screenings look for is called THC-COOH. This substance is stored in your body fat.

“Compared to other drugs, marijuana has the longest detection time, up to months, because the detectable chemicals stay in the body’s fat cells,” explained Nicolas Rossetti, manager of clinical services of Mobile Health, an occupational health center that conducts about 200,000 drug tests in New York City each year.

The vast majority of marijuana detoxes seek to flush the body of any detectable THC. These kits include capsules, chewable tablets, drinks, shampoos, and even mouthwashes to help you pass a saliva test.

However, if a drug test is your concern, detoxes can have additional effects that can make your urine sample look suspicious.

“Cleanses and teas can lower THC levels through their diuretic properties. They make individuals urinate a lot, which technically washes out the kidneys,” said Rossetti.

“This flushing of the kidneys can lower the specific gravity or density of the urine,” he added, “and a low specific gravity indicates contamination on the test, and the specimen could be discounted.”

Also, cleanses and teas may alter the amount of creatinine in the urine, another measure that drug tests look at. Abnormal creatinine levels can indicate contamination, according to Rossetti. This means the tester could assume that you attempted to cheat on your drug test.

While that doesn’t mean a positive test, it does mean the sample is unacceptable, and you’ll likely have to take the test again.

THC can be detected in your blood, urine, and even in your fat cells. The length of time THC remains detectable in the body depends on several factors, including:

  • metabolism and eating habits
  • exercise routine
  • body fat percentage
  • frequency and quantity of marijuana use

Because of all these factors, there is no single standard detection time. Some estimate it can stick around for anywhere from two days to several months.

Urine

Cannabinoid metabolites can remain detectable in urine even after long periods of abstinence. One study found traces of one metabolite, delta 1-THC, in urine as long as four weeks after use.

Fat cells

THC builds up in fat tissue, and from there slowly spreads to the blood. According to a 2013 study, exercise can cause THC to be released from your fat stores and into your blood.

Blood

THC can remain detectable in your blood for as long as seven days, depending on how frequently you use marijuana. Someone who smokes marijuana daily will likely carry marijuana metabolites for longer than someone who smokes infrequently.

As of 2018, marijuana is legal for recreational use in the U.S. in these states: Alaska, California, Colorado, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont, Washington and Washington, D.C. Medical marijuana is approved in over 20 states.

But regardless of its legality, it’s important to remember that marijuana carries with it certain medical risks. Know the risks before you decide to use it or not.

Testing facts

  • The main remnant cannabis drug tests look for is THC.
  • How long THC stays in your body depends on your weight and how much you exercise, among other things.