What to Know About How Long Marijuana Stays in Your System

Medically Reviewed by Jabeen Begum, MD on November 25, 2022
5 min read

With more states legalizing marijuana use, people now have easier access to marijuana. The use of marijuana, or weed, in recent years has grown as more products are created and society’s views on the drug shift. But marijuana is still illegal in some places, and organizations may require you to take a drug test for employment. That raises the question: How long does weed stay in your system? Here are some estimates depending on individual factors and drug test types. 

Tetrahydrocannabinol (THC) is the main component responsible for the euphoric high you get when using marijuana. Your liver processes THC and turns it into metabolites. Over time, THC stored in your body’s tissues and organs is released back into the bloodstream. Your liver eventually breaks down the rest of the stored THC. 

If you use marijuana often, THC builds up in fatty tissues faster than your body can eliminate it. THC can still appear on a drug test many days, weeks, or even months after you use marijuana.

How long weed remains in your body and can show up on drug tests depends on various factors, like:

  • The dosage and frequency of use
  • The amount of THC in the marijuana
  • The way you consume marijuana
  • Your metabolism rate and excretion routes
  • Your gender, hydration levels, body mass index (BMI), overall health, lifestyle, and genetics

Detection times also depend on the drug test used. Typically, weed will remain longer in hair and can be detectable for up to 90 days from the day of use. Tests can detect weed for up to 30 days in your urine, up to 24 hours in your saliva, and up to 12 hours in your blood.

Due to the many factors affecting how long weed stays in your body, detection times vary. Here are the average detection times:

  • Urine: three to seven days
  • Blood: three hours to two days
  • Saliva: one to three days
  • Hair: 30 to 90 days

The most common type of drug test is a urine test. A urine test takes a visual and chemical examination of a urine sample to detect drug compounds that stay in pee. The test is cheap, and results can be ready in as little as 10 minutes.

When you use marijuana, your liver breaks it down into metabolites. About 20% of the metabolites leave your body through urine, while the other 80% are removed as feces. A urine drug test looks for the metabolites in your urine.

On average, urine tests can detect THC from three to seven days. That range will depend on how much marijuana you use and for how long. Tests can detect THC in urine for up to 30 days in a heavy user who uses weed at least once per day.

The detection period for light or moderate use of marijuana is closer to the average duration. You could get a positive urine test result within about four to seven days. 

If you’re a chronic user, more THC will build up and remain in your body. That’s because your body can only break down THC at a specific rate. Your body stores the excess THC in your fat cells. More frequent marijuana use means a longer time for THC to leave your system. Here are the average detoxification times:

  • One-time use: one to three days
  • Moderate use (three times a week): five to seven days
  • Daily use: seven to 14 days
  • Heavy use: 14 to 90 days

A blood test may detect marijuana in blood more quickly than a urine test and up to two days from consumption. However, it's not as commonly used because THC can't be detected in blood for as long as it can be detected in urine.

A hair test is only used for long-term use of marijuana. Having one or two edibles or smoking once a day may not affect your results in a hair test. It takes time for THC to be stored in your hair follicles and build up. If you used weed today, the metabolites would only show up in your hair for seven to 10 days afterward. 

Once the THC metabolites are stored in your hair, they will stay there until you cut your hair. THC can still be detected in new hair growth for up to 90 days.

THC reaches the organs and bloodstream faster when you inhale marijuana as opposed to ingesting edibles. But the THC in edibles can still show up on drug tests.

It takes your liver longer to break down edibles, but it still eventually breaks down the THC into metabolites that leave your body in urine and feces. The rest is absorbed into your bloodstream and spreads to tissues throughout your body. 

Here’s the average time when THC is detected for edibles:

  • Urine: three to 30 days
  • Blood: one to two days
  • Saliva: one to three days
  • Hair: Up to 90 days

Edibles won’t usually last in your system if you use marijuana once in a while. Saliva tests aren’t as effective for edibles. But you should still stay away from edibles between one and three days from your test.

Much of the THC in marijuana is processed by your liver, so boosting your metabolism can help your liver clear THC from your system faster. Exercising and having good hydration are two ways to boost metabolism.

THC in your urine will naturally clear away over time. Still, you can speed up the process by taking detox supplements. Detox supplements speed up your body’s natural detox process, removing weed detectable in urine more quickly.

One of the most effective ways to detox hair is using a technique called the Macujo Method. The main purpose of this method is to clear the metabolites from hair. The process requires opening up the hair cuticles to expose the middle part of the hair follicle where metabolites are stored. The Macujo Method is considered 90% effective to pass a drug test but can be pretty costly.