HOME / Health & Medicine / How Long Does Weed Stay In Your System?

How Long Does Weed Stay In Your System?

Hippy girl portrait smoking weed and wearing sunglasses letterbox

Once considered a hallmark of hippies and counter-culture teens, marijuana use is becoming more mainstream; more than 122 million US adults report having tried weed, with 12% partaking daily. The growing acceptance of cannabis use has been given a boost by the legalization of weed in 17 US states, with a further 26 states allowing cannabis use in some cases. It’s predicted that by 2025, USD$23 billion will be made from legal marijuana sales in the United States. 

Regardless of where you live, there may come a time when you’d like your body to be free of weed traces for an upcoming drug test; let’s explore how long marijuana can stay in your system:

What is marijuana?

First, it’s important to understand what weed is; also known as pot, dope, or a million other names, marijuana is made from the cannabis plant. The psychoactive compound is called tetrahydrocannabinol (THC), and this is what produces the mind-altering effects most commonly associated with recreational use. There are other non-psychoactive compounds in marijuana such as cannabidiol and CBD which are not mind altering, and are used in some other cannabis products like CBD oil

When a person uses weed recreationally, the THC compound produces an effect which makes them feel ‘high’. While marijuana is traditionally inhaled using vapes, pipes, or blunts, but the edibles market is becoming increasingly popular for the discretion and novelty of its products. Edibles can take the form of gummies, lollipops, chocolate, or even gum; candy has approximately 44% of the edible marijuana market share in the US. 

Why you might be drug tested

The Anti-Drug Abuse Act and the Drug-Free Workplace Act of 1988 were introduced by the federal government under the leadership of President Ronald Reagan; these acts encouraged employers to introduce employee drug testing at work. Even if you live in a state where cannabis is legal, there may be situations where you could be drug tested.

If you live in the state of Nevada or New York City, it’s unlikely that you’ll be drug tested for marijuana during the pre-employment process; they have both banned employers from this, citing that what a worker does in their free time should not impact their professional opportunities. Many other states in the US may require pre-employment drug testing; you may also be tested if you play sports, are involved in an accident, or are on parole. If you’re an athlete or starting a new job, it’s natural and even essential to wonder if you’ll pass a drug test after smoking weed

How long does week stay in your system?

The amount of time for which weed is detectable in your system can depend on many factors, such as how frequently you use marijuana and how much you last ingested. It may even be possible for frequent users to have traces of cannabis in their systems for up to 90 days. Detection also depends on which testing method is used; here, we explore some of the approximate detection periods for the most common test types: 

  • Urine testing

Urine testing is the most common form of workplace drug testing, making up approximately 90% of total tests. A urine sample is collected and examined for THC-COOH, the main metabolite of THC. A study conducted by the Mayo Clinic in 2017 reported the following marijuana detection windows based on frequency of weed ingestion:

  • Light users (less than 3 times per week) – 3 days
  • Moderate users (3-4 times per week) – 5-7 days
  • Daily users (once per day) – 10-15 days
  • Heavy users (multiple times per day) – 30+ days
  • Blood testing

Blood testing for marijuana is a less common method, due to its invasive nature and small detection window. As a general rule, weed is detectable in the blood from 4 to 24 hours after ingestion. Frequent users may show a positive result around one week after usage; in some extreme cases, weed has been detected up to 25 days after use. 

  • Saliva testing

A relative newcomer to the drug testing game, oral fluid testing is less invasive than other popular options, and requires only a single swab of saliva. Oral testing can detect drugs and opiates, and is more resistant to contamination than urine analysis testing. If you are tested using this method, you can expect a positive result up to 72 hours after your last drug use.

  • Hair testing

Drug testing can be completed by analyzing a follicle or hair from a person’s body or head. The benefits of hair testing are that it is a relatively non-invasive testing method, and it has the highest potential detection period compared to other drug test methods. Marijuana can be detected in a hair follicle analysis up to three months after your last use. 

  • Home testing

Depending on your reasons for drug testing, you may prefer to take a test privately. Home testing is widely available, and typically involves a self-administered urine test which can provide a result in approximately 5 minutes. These tests are similar to laboratory tests; however, it’s recommended to research the brand before use. 

growing organic cannabis herb on the farm, close up of cannabis leaf

Can I reduce the amount of time for which weed is in my system?

While some products claim to have the ability to quickly remove traces of cannabis from your system, there is no strong evidence that these are effective. Despite some doctors’ positive thoughts on marijuana, it remains a schedule 1 substance even in legalized states; users should be wary of this prior to expected drug testing.

Some marijuana detox products work by flushing out the kidneys to remove THC, a process which may remove creatine and reduce the density of a urine sample. An absence of expected creatine and urine density may produce a contaminated urine test result, meaning that you’d have to provide another sample. Therefore, detox products may be counterproductive. For the best chance at a negative drug test result, abstain from using marijuana for an appropriate period prior to the test. 

Whatever your level of use, it’s important to understand the implications of positive drug test results on your employment status or other aspects of your life. Thoroughly research the legalities of marijuana and drug testing in your state for a better understanding of your obligations and rights.

Active users can reasonably expect traces of weed to remain in their system for up to 30 days. Depending on the method of testing used, you can typically expect a clean test result anywhere from 3 to 30 days after your last ingestion, though this may vary from person to person according to the frequency with which they enjoy marijuana.