Weed is the most popular federally illicit drug in the United States. And employers know it. Indeed, cannabis is the most commonly detected drug in workplace urine drug tests. Setting aside for a moment the totally legitimate criticisms of workplace drug screenings, and debates about the efficacy and accuracy of the tests and the generally humiliating, privacy-invading feel of the whole operation, let’s drill down into one simple question: how long does THC stay in your urine?
Overview: It’s… Complicated
Unfortunately, there’s no simple answer. So let’s simplify things by re-framing the question. Certainly, you’re not here for an academic treatise on cannabinoid metabolism.
More likely, you want to know how long THC stays in your urine because you’re up against a drug test.
So really, the question isn’t how long does THC stay in your urine? The real question is, when will the amount of THC in your urine drop below the threshold for testing positive?
To answer that all-important, make-or-break question, it’s crucial to understand why and how THC ends up in your urine in the first place and the variables that control how quickly your body eliminates it.
How Does THC End Up In Your Pee?
Trick question! THC, or more specifically, the delta-9 THC that gets you high doesn’t end up in your urine at all!
So why fear a urine drug test? Because urine screenings aren’t looking for psychoactive, illicit delta-9 THC molecules. Instead, they detect what your body produces as a waste product after it metabolizes the THC you consume.
That waste product is called a metabolite. THC’s version is THCCOOH, which scientists call a ‘carboxy.’
Your excretory systems are in the business of removing waste metabolites like THCCOOH. To do so, THCCOOH joins up with a uronic acid called glucuronic acid, which passes out of the body in your urine.
Summing up, when you inhale THC in weed smoke, your body rapidly metabolizes it, getting you high just as fast. Your metabolism turns that psychoactive THC into the inactive THCCOOH, which you piss out.
All told, 15 to 20 percent of the THC dose makes its way out of your body by way of acidic urinary metabolites.
How Long Does THC Stay In Your Urine: Examining The Variables
Urine drug tests for weed, then, are essentially trying to detect evidence that your body is still working on eliminating the waste products from your last encounter with THC.
They don’t show when you last smoked. They can’t tell if you were high when you pissed. All they reveal is that someone’s body is still working on eliminating THCCOOH, which means that the body had to have metabolized an illicit amount of THC.
At some point, at least.
With a test so dependent on all of the complex bodily processes involved in human metabolism, no wonder it’s impossible to offer a simple, straightforward answer to the question, how long does THC stay in your urine?
Here, then, are a list of the most influential variables.
As mentioned above, researchers are confident that 15 to 20 percent of a Delta-9 THC dose ends up eliminated via urine. Therefore, the more potent your weed is, the more metabolites will end up in your pee. This also explains how test administrators can correlate the tiny amounts they detect with a real dose of cannabis.
Logically enough, more habitual smokers are vulnerable to urine detection longer than those with more occasional habits. Actually, a lot more.
One-time cannabis users will piss clean in as little as five days, or it could take as long as eight. Smoke just a few times a week? One and a half to two and half weeks and you should be fine. Smoke every day except a couple? It’ll take you a month to a month and a half, or more, to eliminate all the THCCOOH from your system.
And if you’re a daily user, expect a two-month time frame before your urine drug test will come back negative. One major study reported that a subject with daily use habits took 77 days before posting 10 consecutive negative tests.
Here’s a handy table of these average detection windows. Again, these aren’t hard limits. They’re averages. And your body could be extraordinary.
- 1-time use: clean in 5-8 days
- 2-4 times a week: 11-18 days
- 5-6 times a week: 33-48 days
- Daily use: 50-65 days, up to 77
Inhaled Or Ingested?
How long does THC stay in your urine after you eat edibles compared with smoking or vaping weed?
Considering how different an edibles high can feel next to a high from smoking weed, one might expect the THC levels in urine to vary.
In truth, they do.
Edibles will make THC stay in your urine a bit longer, from several hours to an extra day. But that’s not a significant enough degree to make a real difference in the outcome of your test.
In other words, both methods of administering your THC dose are going to put enough THCCOOH in your urine to make you fail a urine drug test.
But because of the way your body processes THC when you eat it—converting it to a psychoactive metabolite called 11-hydroxy-THC, and then into the inactive THCCOOH the test detects—edibles can leave you at risk longer, based on your use habits, compared to smoking or vaping cannabis.
When it comes to your own body, two factors play a key role in how long THC stays in your urine.
The first is your metabolic rate. If you have a higher metabolism, you’ll excrete THCCOOH faster.
The second is your level of hydration. The more fluids you ask your body to process, and the more urine you thus produce, the quicker THC metabolites will leave your body.
Summing Up: How Long Does THC Stay In Your Urine?
Drug urine tests for weed have all kinds of shortcomings and inadequacies.
But they are good at one thing: revealing whether or not the person being tested has consumed cannabis, in some form, at some point in the past. Unfortunately, for many employers with zero tolerance policies, that’s enough to fire you or move on to the next candidate.
Knowing how long THC stays in your urine, therefore, is crucial knowledge for anyone who uses marijuana, regardless of how often or how much.