“How long does THC stay in your system?” You’d think there would be a simple answer, but noooooo! Asking this question is like opening Pandora’s box. You suddenly have to talk about chemistry, biology, physiology, body mass, individual differences, types of drug tests, THC metabolites and testing sensitivity…The list literally goes on and on.
But before your eyes glaze over and you light up a fatty just to cope with that last sentence, there is a light at the end of the psychedelic tunnel. The chemistry and biology and physiology aren’t that difficult, and after a few minutes of reading, you’ll understand what you need to do to pass that looming drug test. Because that’s the real reason you asked how long THC stays in your system, right? That’s okay. We’ve been there. And we’ve done all the difficult research and reading so you don’t have to. Consider this guide Cliff’s Notes to the topic of marijuana and your body.
We’ll start by tracing THC through your body, and see where it goes after you consume it. We’ll touch on the two general categories of drug test and discuss what that means for you ganja habit. Finally, we’ll give you some numbers regarding various methods of testing—saliva, blood, urine, and hair—so you know when you need to stop and when it’s safe to start up again. So, without further ado, let’s rock some science and find out what happens in your body when you consume THC.
What Happens In Your Body When You Consume THC?
Put on your spelunking helmets boys and girls. We’re going to follow THC through your body to find out where it goes after your flight through a blue dream is over.
Pretty much every marijuana experience starts in your mouth. Whether you’re toking a blunt, dabbing some concentrate, or chewing some edibles, THC is almost immediately absorbed into your bloodstream through the soft tissue in your mouth. Yet more THC is absorbed into your system through your lungs and stomach (depending on how you choose to partake, of course), but it all starts with your mouth. This becomes important later on when we talk about testing your saliva for THC. But for now, let’s move to the next link in the physiology chain—your blood.
From you mouth, lungs, and stomach, THC travels into your bloodstream to your brain and other organs. The THC in your blood stream also has an impact on your hair. This becomes important. Even though your blood is constantly circulating and constantly being filtered, THC can remain in your system for quite some time. We’ll discuss the details in the blood section below.
As your blood circulates through your body, one of the “stops” along the way is your liver. Your liver process and cleans your blood so that toxins don’t build up and cause problems elsewhere. It does this by breaking down the “stuff” in the blood into metabolites. Think of these as the results of metabolism. In the case of THC, it’s broken down into the metabolite with the fabulously-convoluted name 11-nor-9-carboxy-delta-9-tetrahydrocannabinol. Thankfully, there’s a shortened version of this name without all the dashes and syllables: THC-COOH.
From the liver, THC-COOH is sent to the tissue in your heart, lungs, kidneys, and body fat for long-term storage. It also continues to circulate in your blood where it can affect another part of your body.
All hair starts growing from a root at the bottom of the follicle (you’ve got 5 million of them on your body and 100,000 on your scalp alone). This root is made up of protein cells and is fed by nutrients (like THC-COOH) in your bloodstream. The unfortunate thing about hair (as it applies to drug testing) is that it holds on to trace elements for a very long time. We’ll see just how long in the hair section below. Before that, we’ve got one more stop in our journey through your body.
Eventually, the THC-COOH in your blood is filtered through your kidneys. Since the THC-COOH is already broken down, it is removed “as is” and passed into your urine and feces. It’s at this point, it warrants concern because most drug tests rely on a urine analysis.
That brings us to a key bit of information regarding the test you have coming up: What is it looking for?
What Is The Test Looking For?
You might think that all drug test are created equal, but they’re not. When it comes to marijuana testing, there are really only two chemicals that you need to be concerned about. We’ll discuss both below. If a drug test has been announced, we recommend trying to find out how you’re being tested. That will give you a good idea what you need to do to pass.
The only way to test for THC directly is through a saliva test. These tests are hyper-accurate, but they are really only good at detecting recent marijuana use. The good news in all of this is that THC doesn’t remain in your saliva for very long. We’ll list the specific numbers in the saliva section below, but unless you smoked the morning of your saliva-based drug test, you should be good.
Testing for THC metabolites (THC-COOH) is the most common procedure. It’s done by taking a sample of blood, urine, or hair, with the urine test being the simplest, easiest, and most affordable (and, therefore, the most readily used).
Once you know what is being tested (saliva, urine, hair?), you can use the numbers listed below, along with the information in Other Factors To Consider, to prepare for your drug test.
How Long Does THC Stay In Your System?
With the exception of the saliva test which looks for THC directly, most tests will look for the metabolite THC-COOH. As you’ll see in the next section, there are several factors that can have a significant influence on the numbers listed below. Take all this into account when deciding how soon you need to stop dating Mary Jane to “cleanse” your system.
Traces of THC can remain in your saliva for between 24 hours and 72 hours. Again, it depends on a number of factors like test sensitivity and how much you’ve smoked. If you’re not a chronic, heavy user, a regular saliva swab will be ineffective after 24 hours. More sensitive tests can detect trace amount up to 72 hours after consumption. But, again, these tests are expensive so they’re not used often. If you’re a chronic, heavy user, a saliva test can detect THC for up to a week after your last smoke.
If you’re a light consumer, THC-COOH can remain in your bloodstream for one to two days. If you’re a heavy consumer, it can remain in your bloodstream for one to seven days. Unfortunately, there’s not a lot you can do if you’re faced with a blood test in either of those time frames. You can’t speed up your liver and your kidneys with external methods. What’s in your blood is in your blood for as long as it takes to work itself out. Thankfully, blood tests aren’t that common.
THC-COOH can be detected in your urine for a month after consumption (for light users). The metabolite can be detected in your urine for two-and-a-half months after consumption if you’re a chronic, heavy user. Urine tests are the most common because they are easy to administer and easy to test. They are also the easiest to beat should the need arise. For a few simple strategies to detox your body, check out our article 13 Of Your Most Pressing Stoner Questions Answered.
A hair drug test is probably the worst option you can face. Sure, a blood test is bad because there’s not a lot you can do to hurry the elimination of THC-COOH, but it will work itself out in a week. Not so with your hair. Traces of THC-COOH can remain in the cells for ninety days or longer. Yes, that’s three months or more. Thankfully, hair tests are not that common, so it’s not something you really have to worry about. As we mentioned before, we always recommend that you try to find out how (and on what part of your body) the test will be performed. If it’s a saliva swab looking for THC, you’re probably safe after 24 hours. If it’s a hair test in two weeks and you just smoked last night, you’re probably screwed.
Other Factors To Remember
These factors will affect how long the THC stays in your system, regardless of whether it’s your saliva, your blood, or your urine.
- The strength of your weed—More potent strains mean more THC-COOH in your blood.
- The frequency with which you use—Smoking more often means more metabolite in your blood.
- The method by which you partake—THC obtained through edibles remains in your system longer than THC that is smoked.
- The speed of your metabolism—A faster metabolism will move the THC-COOH through your system sooner.
- Your body fat percentage—Higher body fat means longer THC-COOH processing times.
- Your general health—If you’re on the healthier side, your body is able to detox faster.
- Do you take other drugs or supplements?—The presence of other drugs, or even supplements, can slow down the elimination of THC-COOH.