How to Beat a Urine Test for Weed

By Gabriel Bell 

Despite its increasing legality on a state level (yesssss!), marijuana use remains banned by the federal government and a perfectly good reason for any employer or school to bounce your stoner ass.

This begs the questions: How long is pot detectable in your system and is there any way to mask or remove its presence?

There are multiple ways to test for pot. While immediate in their results, blood, sweat, and salvia tests really only determine if you’ve used in the last couple of days at best. Marijuana remains detectable in hair for 90 days or more, though testing for its presence there takes up to seven days and costs more than other methods.

Because urine testing returns a result in hours, has an effectiveness of days to weeks, and is relatively affordable, it’s become the go-to option for most employers and schools and the only one the government uses. Luckily for the pothead, this most popular method is also the only one that’s fungible.

To explain how you can mess with the test, we have to get science-y on you. Urine tests  look for THC-COOH, a byproduct of your metabolism caused by THC that hides out in your fat cells. By and large, the amount testers call a “positive” is about 50 nanograms of THC-COOH per milliliter of urine (though some testers will call it at 15ng/ml, others at 100ng/ml).

Because THC-COOH is a metabolite, its continued detectability in your system depends on your individual metabolism. Maybe you have a high one thanks to diet, exercise and genetics. Maybe you have a low one due to inactivity, your DNA, or other factors. The higher your metabolism, the faster you will burn through those offending metabolites. The lower your metabolism, the slower.

So, while studies have produced a general timeline for THC-COOH’s presence in the urine of the chronic smoker, there can be wide variance from person to person. Most regular smokers produce less than 50ng/ml of THC-COOH—the “positive” level of most tests—within two weeks of their last use and go down below 15mg/ml—the floor for the most sensitive tests—within a month after their final toke. For those with slower metabolisms, it may take over six weeks to get below 50ng/ml and well over two months to get under the 15ng/ml cutoff.

Simply put: If you’re a chronic smoker, there’s better than an 80% percent chance that you’ll pass a test anywhere from 10 days to two weeks after your last smoke. Still, if you’re wildly out of shape and have a very stringent tester, that timeline could extend to 60 days or more. Note that very occasional or rare users will likely pass a test within a week of ceasing smoking.

So how do you game this? Obviously, having a high metabolism helps greatly, so regular exercise, a proper diet, and keeping slim are important. (P.S., with the right weed going to the gym can be really fun.) However, in an ironic twist, working out in the days before a test could free THC-COOH stored in fat cells, triggering a positive. So, work out all the time, but stop in days before a test.

Hydration is also key as the more water that washes through your system, the more diluted your urine is. For both lowering weed detectability and improving your general health, you should always—test or no—drink enough so that your urine is close to clear (your kidneys and skin will thank you).

In the days leading up to a test, keeping fully hydrated is even more important. Again, you’re trying to shift the balance in nanograms of THC-COOH per milliliter of urine. The more liquid you consume—three liters a day in the days before your test, two liters in the hours before it—the lower that percentage will be.

The speed bump here is that by flushing your system with all this water, you’re lowering the nanograms per milliliter of other substances in your system. Knowing that people overhydrate before tests, many labs check to see if your levels of creatinine or Vitamin-B are abnormally low. If they find that they are, they’ll likely test you again.

Beating this is pretty straightforward. Simply use creatinine and Vitamin-B supplements before your test (both are easily available in health stores and online). For dosing, follow the label on your creatinine supplement and take 50ml to 100ml of a B complex containing B-2 and B-12. Don’t overdose on either as that can trigger a retest as well.

Now, there is a huge variety of products that promise to help you beat a urine test. Some claim to clean out your system. Some supposedly contain masking agents. There’s even synthetic urine out there. Thanks to FDA rules, however, none of them have to back up their claims with proof. The few effective ones help you up your metabolism or overhydrate you and then mask with creatinine and Vitamin-B. Basically, none of them do what you can’t already do yourself with a little bit of exercise, a lot of water, and a few supplements. Try them if you want, but we can’t in good conscience recommend any.