Navigation

How Long Does Weed Stay in Your System? [Precise Calculator]

Weed and edibles stay in the system

Today you are going to learn exactly how long THC (including edibles) stays in your system and how to speed up the detox process.

The main psychoactive compound in cannabis—THC—can stay in the body for days and weeks.

The detection window depends on the testing method: Most common are blood, urine, sweat, saliva and hair testing.

However, have in mind that:

  • Most of the tests in use today detect THC in levels above 50 ng/dL, so until you get below that level you will keep testing positive.
  • Body fat percentage plays a huge role in how quickly you are able to flush THC out—the more body fat you have, the longer the THC will stay in your system as that’s where it’s stored.
  • Only THC is detectable in tests while other cannabinoids (such as CBD) are not.

How long does weed stay in your system (Chart)

How long does weed stay in your system (Chart)

Depending on the testing method, here is how long THC stays in your system:

  • Blood — 1 to 7 days
  • Urine — 7 to 30 days
  • Saliva — 1 to 7 days

Precise THC detox calculator

While the chart does provide a decent basic overview, it’s not exactly precise.

We’ve made an accurate THC drug test calculator which takes into account two things that influence metabolism of THC the most: Body fat percentage and urine THC metabolite levels.

Body fat (%):

Urine metabolite level (ng/mL):

Time to clear THC (days):

As you can see, to use this calculator you’ll need to know your urine metabolite levels. Metabolite levels of frequent users hover at around 200-250 ng/mL, measured one day after using cannabis.

The only way to get exact numbers is by using a home kit THC test—don’t go for the most basic one as you’ll need a “multi-level” test that shows THC levels in ng/mL. Here is a cheap multi-level test I found on Amazon.

If you don’t know what your body fat percentage is, take a look at this visual comparison for a rough estimate.

Chart to assess body fat levels visually

As I’ve said, there are several popular cannabis testing methods and passing them depends on the testing method and the frequency of cannabis use.

Here’s a quick overview.

Weed stays in urine from 7-70 days

Urine testing does not look for THC, but a non-psychoactive metabolic intermediate—THC-COOH.

After using cannabis, our liver metabolizes THC into THC-COOH which is then stored in urine.

Again, for how long THC stays in urine depends mostly on the frequency of use.

If you’ve used marijuana just once, weed will stay in your urine for about 7 days.

If you’ve smoked 2 to 4 times recently but didn’t use it since, weed will stay in your urine for 10 to 18 days.

If you use cannabis 5 or 6 times a week, it will stay in your urine for 30 to 48 days.

Medical marijuana users and daily recreational users need a bit more time to completely detox—about 50 to even 70 days.

Weed stays in blood from 1 to 7 days

THC is only detectable in blood for a short amount of time, hence this testing method is not that popular anymore.

After smoking, THC runs through the blood and gets stored into fat, where it stays for longer periods of time.

In general, if you’re not a regular smoker and you only took a few puffs, weed will stay in your blood for 1-2 days.

If you’ve used cannabis a few times in the past week, THC will stay in your blood for about 3 days afterward.

Yet, if you are a regular, everyday user you’ll need around 7 days to flush THC out completely.

Weed stays in hair for up to 90 days

With this testing method, THC can be detected from just a single hair sample taken 1.5 inches from the scalp.

This makes the hair test really scary and accurate—it can detect even picograms of THC.

Note: If your first hair sample tests positive for weed, they might ask you to provide a second sample.

Weed stays in saliva for 1-7 days

Saliva marijuana tests are usually used by the police, through devices like the Dräger 3000.

Weed can be detected in saliva just an hour after consuming cannabis.

If you only used marijuana once, it can stay in your saliva for up to 24 hours.

If you are an occasional user, weed can stay in your saliva for up to 72 hours.

If you are a regular heavy user (or a daily medical user), weed can stay in your saliva for up to a week.

Roadside saliva tests have been very controversial recently. The problem is that you can test positive to THC without even being high, so it’s still very difficult to determine if the driver is actually impaired or not.

Weed stays in sweat for 7-28 days

Sweat tests are not that common and they are usually used for monitoring patients during drug rehab treatments and employment programs.

THC metabolites can be detected in sweat for about one to four weeks.

This depends on two factors: How much sweat you produce and how much you smoke.

Also take into account environmental factors, such as temperature and air humidity.

Here’s how this test works:

THC sweat patches are applied to the skin and are usually worn from 7 to 14 days. After that period, patches are taken off for testing.

The amount of produced sweat is subjective, and so the accuracy of this testing method is somewhat limited—and it’s hard to control if someone wore the patch all the time, of course.

How long do edibles stay in your system?

Consumption method is very important when it comes to cannabis testing.

For example, when you eat a cannabis brownie, it takes much longer to get “high” when compared to smoking.

When you eat an edible, cannabis has to go through the entire digestion process before cannabinoids enter the bloodstream.

That’s why edibles stay in your system for 7 to 30 days.

Just 5 days after eating an edible, 80 to 90% of THC gets flushed out but the remaining 10% can be detected for up to 4 weeks.

How to speed up the THC detox process?

The best way to flush THC out of your system and pass the test is pretty simple—total abstinence for a set period of time.

If you know you’re going to get tested for cannabis, I suggest you reverse engineer the chart above and stay cannabis-free for that time period.

If it’s already too late and you don’t have the time, there are a few things you can do to speed up the detox process.

These tips could help, but there are no guarantees they will work.

Take note that research showed that people with a fast metabolism, lower body fat percentage, and lower BMI can flush THC out faster than people with standard BMI.

But, here is what you can do.

1) Drink plenty of water

Staying hydrated is essential for your health in general. So if you want to flush marijuana out your system, start drinking a lot of water a few days before the test.

Keep in mind that drinking a lot of water can make your urine clear so this could look suspicious as well.

2) Eat the right foods

As THC is stored in fat, you’ll need to avoid fatty and greasy foods as well as things rich in sugar and sodium. That means no junk food and red meat.

You’ll need a lot of food rich in fiber and antioxidants so stick to fruits, vegetables, and whole grains to detox faster.

Also, vitamin C should be your new best friend. Lemonades and citrus juices are full of electrolytes which are great detoxing agents. Tea will also help you flush THC out, so drink a few cups of green, black or white tea a couple of days before your test.

Vitamin B3 is great when you’re looking to cleanse your system from just about anything. Avocados and potatoes are one of the biggest natural sources of vitamin B3 (also known as niacin).

3) Exercise and sweat

Cardio is the best way to burn fat, which is also where THC metabolites live. By exercising, we sweat more, excrete fluids and we eventually speed up the THC detox.

A workout that mixes cardio and strength would be the best to flush marijuana out, starting a few weeks prior to testing.

But, there is one tricky thing when it comes to exercising. Don’t do it on the day of testing. In fact, try to avoid all exercise a couple of days before the big day.

Even though exercise burns fat, that process also releases more THC metabolites into your blood, which could be a bad choice for the testing day.

If you’re really worried about the test, a sauna can also do wonders.

4) Get a lot of sleep

It’s now common knowledge that cannabis relieves stress and induces sleep. However, if you have to take a drug test you’ll have to get some rest without weed.

When we sleep, our whole body recovers for the following day. It’s our own, natural detox mechanism.

So, a few days (or weeks) before taking the test, try to get as much sleep as possible. Give yourself a few nights off and try to go to bed earlier than usual.

About the author
Helena Miles

Experienced journalist with a decade-long experience of researching cannabis. She has been featured in many prominent outlets, such as The Growth Op, National Post and The Province.

Comments (96)

User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
User Avatar
Leave a Reply

Your email address will not be published.

Green Camp Logo

Please confirm your age

Are you over 19 years of age (over 18 in Alberta and Quebec)?

By entering, you agree to Greencamp's Terms of Service and Privacy Policy.