The need to pass a drug test often arises suddenly, at such short notice that it’s impossible to clear your body of both THC and its metabolites (the chemicals tested for by modern drug panel assays). While it’s true that there are natural ways to cleanse your body of THC, these methods take much longer than most people have the time for, especially if you’re a long-term or heavy cannabis consumer.

So, if you can’t clear your body of THC and its metabolites in time, how are you supposed to pass a drug test? Don’t despair! Just because you don’t have the time to purge your system of THC doesn’t mean all hope is lost. Here, we’ll discuss how to pass that drug test!

How THC Is Stored In the Body

Before we begin, it’s important to lay out why a simple detox won’t do for ridding THC from your system. When you consume cannabis (through any mode, whether it’s smoking, edibles, or vaping), THC levels in the blood rise and the THC is metabolized into one of several inactive chemicals. The primary metabolite, or chemical byproduct, of THC, is tetrahydrocannabinol carboxylic acid or THC-COOH for short. The THC itself produces your “high,” while the metabolites are simply the leftovers of the metabolism of THC by your body.

Here’s where it gets a little unfortunate for cannabis consumers: THC and its metabolites are lipid-soluble, meaning they aren’t dissolved in water but in fats. This means that, rather than getting flushed through your kidneys and exiting the body quickly, THC can linger in the fatty tissue of your body for months, depending on how frequently you consume cannabis. While many other, more potentially harmful drugs are out of your system in less than a week, THC is different, and no cleanse is going to clear your system of THC and its metabolites in a single day.

So what are you supposed to do if there’s no way to get clean in time? First of all, don’t panic! You still have several options, which we’ll discuss in detail. We’ve fully vetted each of the products we’re about to talk about, so trust us when we say that these options will help even the heaviest cannabis consumers.

Option 1:  Substitution

This is our favorite option, as it works for most drug screens and guarantees you’ll pass your test. The only exception is supervised drug screens, which we’ll talk about later. For the substitution method, you’ll need to obtain clean urine, either from someone you know or from a reputable source like TestClear.

We like TestClear’s Powdered Urine Kit for a number of reasons: it’s convenient, it’s simple, and it works every time. Simply add water to the powder in the vial, which holds plenty of volume for your sample at 50 mL, about 45 minutes before your test. Then, use the air-activated heater to warm the specimen up to between 90 and 99 degrees—the high-quality, reusable temperature strip lets you know when you’re good to go. You can also purchase extra heaters at the time of purchase, that way you know you’re covered in the event of a delay.

This is the stuff they use to calibrate drug tests, so it’s guaranteed to pass every time. For this reason, it’s our exclusive recommendation for a completely foolproof result. If you’re taking an unsupervised drug test, the substitution method is going to be your best, most reliable option.

Option 2:  Dilution

Let’s be clear: there is no anecdotal “system flushing” technique that is supported by science. The biggest problem with dilution is that testing facilities have caught on to the flushing strategy, and have procedures in place to flag samples that have been diluted beyond normal levels. This means that, in order to pass, you must ensure that the sample is diluted enough so as not to test positive while staying below the threshold for raising eyebrows at the testing facility. It should be noted that this method probably won’t work for heavy consumers, but if you only smoke once or twice a week, dilution may work for you.

So how do you dilute your urine? The first thing to do is abstain immediately, as soon as you are notified of the drug test. This may seem obvious, but continuing to consume certainly won’t do you any favors. In this vein, the longer you can abstain prior to the test, the better your chances of passing are. The aggregate levels of THC and its metabolites will continue to decrease the longer you abstain for.

It also helps to exercise in the time leading up to your test, though it only helps if you have enough time. This is because exercise increases the rate at which your body releases stored THC and its metabolites, which definitely isn’t helpful right before you’re scheduled to pee into a cup. For this reason, we suggest refraining from exercise in the few days before your test, but if you have a few weeks to plan, then hit the treadmill and sweat off some of those cannabinoids!

Make sure you’re eating healthy foods to keep your urine sample as close to normal as possible. Drink enough water and eat sensibly, supplementing with natural diuretics like coffee and cranberry juice if you desire. Then, about 24 hours before the test, take a vitamin B complex to help return the yellow color to your sample, making it appear less diluted. It’s also a good idea to substitute with creatine, as its absence serves as a red flag for dilution in particular.

Before the test, it’s a good idea to test yourself using an at-home marijuana drug testing kit. This will allow you to test yourself and find out if you’re testing clean or not. If it comes to be the day of the test and you still aren’t testing under the threshold for marijuana, you still have one more option: masking, or adulteration.

Option 3:  Adulteration

If you’re down to a day or two before the test, you aren’t testing clean, and powdered urine is out of the question, you have one more option at your disposal. It’s not our favorite, but it works in a pinch: using detox products to adulterate your urine sample, allowing it to temporarily test clean.

We stick by what we said before: no product can completely cleanse your body of THC in a single day. However, these products work by masking THC and its metabolites in your urine, allowing them to fly under the radar on the test and helping you pass.

We like MegaClean Cleansing Drink (shown in image below) because it works, it’s easy to use, and it’s surprisingly tasty. Take the entire contents of the bottle about 3 hours before your test, then wait 15 minutes and refill the bottle with water and consume that. Keep drinking water and be sure to urinate frequently in the hours leading up to your test. MegaClean’s effects are at their peak at 3 hours from ingestion, so timing is key.

The MegaClean Cleansing Drink will help even the heaviest consumers pass a drug test on short notice. However, if you have more time, we suggest using the Toxin Rid product line from TestClear, which is available in 2, 3, 4, 5, and 10-day detox programs. All of the Toxin Rid products come with a Money Back Guarantee, meaning these products really work. We prefer ordering from TestClearbecause products can be shipped overnight—perfect for passing that last minute drug test.

A Quick Note About CBD & Drug Testing

If drug testing is a part of the conditions of your employment, you might be concerned about the potential of CBD to cause you to test positive for THC. This isn’t an unfounded concern — however, there isn’t exactly a cut-and-dry way to answer it.

Much of the data we have about CBD is anecdotal, and its potential impact on drug testing is no exception.  There are very few peer-reviewed studies on the subject, and the ones available paint a rather murky picture:  avoiding full-spectrum products containing traces of THC can reduce your risk of a false positive, but that may not eliminate the risk entirely.  A single study (as yet unconfirmed) suggests that even isolate-based products may not be completely risk-free under certain circumstances.

If you are concerned about passing a drug test, you’ll need to consider this potential risk when deciding whether CBD is right for you. To learn more about the science of CBD and drug testing, check out our article for a more thorough discussion of how to minimize your risk of a false positive.


Regardless of the method you choose, it’s important to stick to your plan. If you aren’t using the powdered urine samples, then you’ll need to prepare for your test and make sure that you time your use of any adulterant products carefully for maximum effectiveness. Be sure to read all instructions and follow them closely, and test yourself beforehand if possible.

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