How Long Does Weed Stay in Your System? What Affects Detection

The effects of marijuana fade rather quickly, but the drug can be detected in your body even weeks after use. Sometimes, the active ingredients and breakdown products of weed can stay in your system for up to 90 days, but of course, this depends on how much marijuana you’ve been using. 

Even if there are several states in the US that have made medical and recreational marijuana use legal for adults over 21, the federal government still classifies marijuana as a Schedule I controlled substance

Because of this, people in other states are still being tested on the use of marijuana. In most cases, legal and healthcare professionals need to take randomized testing and see if an individual has been using marijuana for a certain period. 

If you’re curious to learn more about marijuana and how long THC can stay in your body, keep reading. In this article, you’ll find everything you need to know about THC and how long it can remain in your body. Let’s take a look!

How Long Does THC Stay In Your System?

The half-life of a drug refers to how long it takes for half of the drug to be metabolized and eliminated from your bloodstream. Although there are many marijuana strains and there are various cannabinoids present, THC is what common drug tests look for. 

When THC is in our body, it breaks down rapidly and is modified into metabolites. You should know that there are at least 80 types of metabolites formed from THC, all of which have their own effects on our body’s endocannabinoid system. Essentially, these metabolites are retained in our body fat and eliminated through our feces and urine. 

The half-life of THC metabolites varies; some can be eliminated within 20 hours, while some can stay in our body fat for up to two weeks. Since it takes five to six half-lives for a substance to be detected in the body, one-time use may not be detectable after five to eight days. 

  • Urine

When you take a urine test, results will only show recent marijuana use; current intoxication and impairment aren’t detected. This because the time between your body breaking down the THC to metabolites is crucial is eliminated through urine. 

Since there are companies with zero tolerance for drug use, the urine test is the most common test employers use to detect the recent use of drugs. With that being said, you should know that THC can be detected between three days to a month or longer in urine, depending on your use. 

urine drug test kit
Weed Drug Test
  • Blood and Saliva

Since marijuana can only stay in the bloodstream for a short period, blood tests for marijuana use aren’t recommended. However, exceptions are during automobile accidents and roadside sobriety checks since THC can be detected in saliva for up to 48 hours and 36 hours in blood. 

Even if blood and saliva tests can show current intoxication, you cannot indicate the level of intoxication or impairment. 

  • Hair

Most often than not, daily or frequent cannabis consumption is detectable through a hair test up to three months later. However, hair tests aren’t always reliable in detecting infrequent cannabis use.

False Positive Testing with Marijuana

When you’re being tested for drug use in the workplace for marijuana, this may entail first screening the sample with an immunoassay test. After these tests, which are also known as EMIT or RIA, and you receive a positive result, the sample will be screened with a GCMS. 

GCMS is a more accurate test; therefore, false positives are rare. With that, no known substances can cause a marijuana urine test to give you false-positive results. 

Factors That Affect the Detection Time of Marijuana In the Body

Several factors affect the length of time marijuana remains in the body. These factors include how frequently you use the drug, your body mass, sex, hydration levels, and more. 

  • Sex

Studies show that women metabolize THC at a slower rate since women have a slightly higher body fat level than their male counterparts.

  • Metabolism

Metabolism also plays a crucial role in how long the drug remains in your system. This factor can be impacted by your age, physical activity, and certain health conditions. With that being said, your lifestyle can also have an effect on how long THC can stay in your system. For example, if you exercise regularly and have a balanced diet, toxins can be eliminated from your body quite easily, as compared to people who are more sedentary. 

  • Body Mass Index

Since THC metabolites are stored in fat cells in our bodies, this means that the higher body fat or BMI you have, the slower you’ll be able to metabolize and eliminate marijuana in your body. 

  • Hydration

When your body doesn’t have enough water and is constantly dehydrated, more concentrations of THC can stay in your body. However, drinking huge amounts of water won’t make you pass a drug test, but it can dilute it and may let you retake the drug test. 

  • Smoking, Vaping, and Edibles

The method of how you take marijuana will also impact its detection. If you smoke or vape marijuana, THC levels in the body may drop faster than when you ingest it. When you take edibles, it can take longer to break down and leave your system. 

Does Frequency of Use Determine How Long It Stays in Your System?

The length of time that marijuana remains in your body is affected by how often you use the drug, how much you use it, and how long you’ve been using it. 

People who use marijuana frequently have tested positive in the drug tests even after 45 days since their last use, and those who use marijuana heavily have tested positive even after 90 days since their last use. 

Does Smoking or Eating THC Products Take Into Account How Long THC Would Stay In Your System?

  • Smoking a Joint: Smoking marijuana has been the most common method of using marijuana. After you inhale the drug, THC enters your lungs and passes through your bloodstream, carrying the chemical to your brain. You feel the effects quicker compared to an edible. Because of this, speaking through smoking will last for a shorter period.
  • Eating an Edible: In some cases, cannabis and other extracted active ingredients are mixed into different foods, like cookies, brownies, and candies. However, the potency of edibles can vary greatly.

    After eating edibles, THC is absorbed into the bloodstream and can take 30 minutes to an hour before it reaches the brain. In that regard, the effects of edibles will last much longer.

The Bottom Line: There are Several Factors That Affect the Detection of Marijuana in Your Urine

Factors like how often you ingest marijuana, how much you take, and other physical factors can affect how your body metabolizes and eliminates the drug. So if you want to stop using marijuana or help someone sober up, knowing these factors that help detect marijuana usage can be extremely helpful.