How Long Does THC (Marijuana) Stay In Your System: Urine, Hair And Blood

Cannabis users who want to pass a drug test need to consider that the substance and its related compounds can stay in people's systems for up to several months.

How long marijuana stays in a person's system depends on several factors, such as frequency of use, the potency of tetrahydrocannabinol (THC) and metabolism, among others, according to Tennessee-based healthcare company American Addiction Centers.

THC, the most well-known psychoactive compound in marijuana, is usually stored in organs and fatty tissues before being broken down in the liver into metabolites, which are then excreted in urine and stool, according to Healthline.

However, frequent users may accumulate more THC than what their bodies can flush out.

The compound and its byproducts can be detectable for up to three months depending on whether someone uses marijuana less than twice a week (infrequent user), several times per week (regular user) or daily (chronic user), Insider reported.

Weed can typically be detected in hair for up to 90 days after last consumption, for most users. But while the hair test is less invasive and takes less time than urine and blood tests, it has been known to cause false positives.

A urine test, which is the most common drug testing method, can detect THC byproducts for more than 30 days in chronic users. But regular users should expect them to be flushed out between seven to 21 days, while infrequent users will have their systems cleared between one to three days after last consumption.

The presence of THC in the blood is relatively shorter compared to hair and urine, with blood tests usually only being able to detect the substance between one to two days after last use for infrequent and regular users. Chronic users can test positive for up to seven days.

Some reports suggested that tests on both blood and urine can detect marijuana in a chronic user's system for up to three months, according to Drugs.com.

Saliva also has a short detection period of one to three days after last consumption, but some chronic users may still have detectable marijuana in their system for up to 29 days, Healthline said, citing a review published in 2014.

When it comes to speeding up the process of getting marijuana out of someone's system, experts agreed that the best way to accomplish that is for the person to stop using marijuana products.

"There are products and lots of anecdotal stories on what will work, but the only way to truly clean out your system is to stop consuming," April Hatch, a registered nurse who co-founded the education group Cannabis Care Team, was quoted as saying by Insider.

Drinking water, eating healthy or "sweating it out" will not help remove marijuana from the system, according to the outlet.

There are currently 18 states that allow for the adult use of marijuana, while 36 allow the substance's medical use, a report by Forbes said.