How long does weed stay in your system? Here’s everything you need to know

By Alma Fabiani

Updated Jun 22, 2021 at 03:25 PM

Reading time: 2 minutes

On Tuesday 20 March 2021, many of us will be celebrating 420, also known as weed day. After the year the COVID-19 pandemic made us go through, we deserve this sesh, to say the least. But, as fun as 420 is, we’re also aware that for some, smoking cannabis—and therefore having it in your system for a little longer—can be an issue for many different reasons. That’s why, in anticipation of the day, we tell you everything you need to know about exactly how long for traces of your Tuesday smoking sesh might still be detectable in your system. You’re welcome!

It varies depending on the dose you consume

Marijuana is usually detectable in bodily fluids for one to 30 days after last use. And just like with other drugs, cannabis may also be detectable in your hair for several months. The type of cannabis you consume also plays a factor. For example, using THC capsules in Canada versus edibles will have a different impact on your body and how long it stays in your system.

Weed detection windows depend on how much you smoke (or ingest), as well as how often. In general, higher doses and more frequent use are associated with longer detection times. For daily users, it may be detectable for several months after last use. The longest-reported detection times are over 90 days.

So, how long is weed detectable in your system via different types of drug testing?

Blood testing

According to an article in Therapeutic Drug Monitoring, weed is typically detectable in the blood for one to two days. However, in some cases, it’s been detected after 25 days! As mentioned above, chronic heavy use increases the length of time that it can be detected.

Weed becomes detectable in someone’s bloodstream within seconds of inhalation. It’s distributed to the tissues, while some of it is reabsorbed in the blood and broken down. Its metabolites—which are what drug testing methods will notice—may remain in the bloodstream for days.

Urine testing

Urine testing tends to be the most common testing method when it comes to cannabis usage. Weed is detectable in urine for the following amounts of time after last use:

Occasional users (up to three times a week): 3 days
– Moderate users (four times a week): 5 to 7 days
– Chronic users (daily): 10 to 15 days
– Chronic heavy users (multiple times a day): more than 30 days

Saliva testing

According to a 2014 research on cannabinoids in oral fluid, weed is detectable in saliva for the following amounts of time after last use:

– Occasional users: 1 to 3 days
– Chronic users: 1 to 29 days

Weed can enter the saliva through smoking and exposure to smoke. However, its metabolites are only present in saliva when it has been smoked or ingested, so no, your secondhand high doesn’t count.

Hair testing

Hair follicle tests assess drug use for up to 90 days. After use, weed reaches the hair follicles via small blood vessels, which is why trace amounts may remain in the hair.

“Since hair grows approximately 0.5 inches per month, a 1.5-inch hair segment taken close to the scalp can provide a window of weed use for the past three months,” writes Healthline.

Is there anything you should do to metabolise it faster?

Unfortunately, there isn’t much you can do to speed up the amount of time it takes for weed to leave your system. Once it’s entered your system, your body simply needs time to break it down. Exercising, eating healthy, and staying hydrated may help, but not drastically.

Online, many advise drinking a lot of water to dilute your urine, and then using herbal supplements such as creatinine or vitamin B-12 to mask the dilution. These kits aren’t fully reliable.

All in all, weed may stay in your system anywhere from several days to several months after last use. Detection windows depend on the drug test used and other factors such as whether you smoke or ingest weed on a regular basis. So don’t go too hard this Tuesday if you’re worried about the aftermath of your 420 celebration.

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