how to pass a weed test

How To Eliminate THC From Your System: A Complete Guide

Drug tests are never fun, especially when you’re a regular cannabis user. But fear not; if you’ve got a drug test coming up, here are some simple ways to help flush THC from your body.

Use this guide to help eliminate THC from your system!

  • 1. How long does cannabis stay in your system?
  • 2. Factors that affect how quickly you metabolise THC
  • 2.a. Dosage and frequency of use
  • 2.b. Body fat and overall metabolic rate
  • 2.c. Sensitivity of the drug test
  • 3. Drug tests and detection times
  • 3.a. Urine testing
  • 3.b. Saliva testing
  • 3.c. Blood testing
  • 3.d. Hair testing
  • 4. How to get THC out of your system
  • 5. How to ingest activated charcoal
  • 5.a. Charcoal bread recipe
  • 6. Wrapping up: How to eliminate THC from your system
  • 1. How long does cannabis stay in your system?
  • 2. Factors that affect how quickly you metabolise THC
  • 2.a. Dosage and frequency of use
  • 2.b. Body fat and overall metabolic rate
  • 2.c. Sensitivity of the drug test
  • 3. Drug tests and detection times
  • 3.a. Urine testing
  • 3.b. Saliva testing
  • 3.c. Blood testing
  • 3.d. Hair testing
  • 4. How to get THC out of your system
  • 5. How to ingest activated charcoal
  • 5.a. Charcoal bread recipe
  • 6. Wrapping up: How to eliminate THC from your system

Good news! You just got your dream job. But, your new career comes with a catch—a zero tolerance drug policy. Do you give up weed? We know that might be intolerable or even impossible. There are many reasons why people choose to use cannabis, and we don’t judge; we just puff, puff, pass.

So, you make your best choice and continue to partake. But, you suddenly find yourself facing a drug test. Eep! What to do!? Read on to find out how to get THC out of your system.


The length of time cannabis stays in your system is affected by your unique biology and habits. While everyone is different, cannabis is usually detectable in fluids like urine and saliva from 1–30 days after last use. It may be detectable in hair for months.

THC is metabolised in the liver, where it gets broken down into over 80 metabolites. Eventually, THC and its metabolites are excreted, leaving your system. However, many of these compounds linger in your system longer than THC itself. Most drug tests are designed to detect certain metabolites, like tetrahydrocannabinol carboxylic acid (THC-COOH).


So, how long does it take for any trace of weed to leave your system? Your own THC timeline relies on numerous factors, including:

• How much/how frequently you consume cannabis
• How much body fat you have/metabolic rate
• How sensitive the drug test is/type of drug test


The amount (and frequency) of cannabis you regularly consume is perhaps the biggest factor. This one really is a no-brainer: The more cannabis you consume, the more metabolites there are knocking around in your body. Cannabis taken orally, like edibles, may also linger in your system longer than smoking.

Consumption rules apply to both individual doses and long-term habits. Two grams of weed will take longer to leave your system than one. Weed that’s more potent will take more time to clear out too. If you’re an occasional user, your system will eliminate THC faster. So, take note! If you’re a chronic user of cannabis, you may need extra time to abstain before you can pass a drug test.


THC is detectable for longer in chronic users because THC metabolites get stored in fat cells (they are lipid soluble). A person with less body fat will store fewer of these molecules, and a person with more body fat will store more. That’s why sex can sometimes be a factor as well. Females tend to have more body fat than males, so women may metabolise cannabinoids more slowly.

A person’s overall metabolic rate also plays a large role. Some people can burn calories just by sitting around, while others struggle to lose weight even with an active lifestyle. Those with a faster metabolism will process and eliminate cannabinoid metabolites more quickly. Just be aware, if you exercise heavily before a drug test, the fat you burn could release more THC metabolites into your system, causing a temporary spike.


Different drug tests—urine, hair, saliva, blood—have different detection windows. Many, like hair and urine screenings, measure the THC metabolite THC-COOH, while blood tests measure levels of THC itself. Of all the standard testing methods, urine testing is by far the most common [1] . If you’re being drug tested at work, it’s almost always going to be a urine test.

Test sensitivity refers to the cutoff concentration of THC or its metabolites, above which a test is considered positive. The cutoff for most cannabis urine tests is 50ng/ml of THC-COOH. However, it is possible for the cutoff to be set as low as 15ng/ml. The more sensitive the test, the longer the detection window is.


According to available research, these are the most common detection windows for different drug tests. Keep in mind, the timeline varies according to your unique physiology and personal habits.


Cannabis and its metabolites are detectable in urine [2] for varying amounts of time after last use, depending on how frequent of a user you are:

Occasional user (one to three times per week): 3 days
Moderate user (four times per week): 5–7 days
Chronic user (daily): 10–15 days
Heavy chronic user (multiple times per day): 30+ days

This is, of course, assuming the test sensitivity cutoff is a standard 50ng/ml.


Roadside saliva tests may be used to detect impaired driving in some jurisdictions where cannabis is legal. According to a scientific review [3] , cannabis can typically be detected in saliva for:

Occasional users: 1–3 days
Chronic users: up to 29 days


Blood testing is relatively costly and invasive, making it less common than other testing methods. However, blood tests may be used in some clinical or emergency settings. Unlike urine tests, which detect metabolites, blood tests typically look for the presence of THC itself. THC is almost instantly detectable in the blood upon inhaling cannabis, making blood tests ideal for determining recent drug use.

Research shows [4] that cannabis remains detectable in blood for 1–2 days. However, in certain cases it has been detected up to 25 days later. Heavy, chronic use of cannabis can increase the length of the detection window.


Following consumption of cannabis, THC reaches the hair follicles through small blood vessels. Trace amounts can be detected in hair for up to 90 days, as confirmed by a 2015 study [5] . Typically, a 4cm section of hair taken from near the scalp indicates cannabis use over a three month period (hair grows at an approximate rate of 1.2–1.5cm per month).

If you’re required to take a hair follicle drug test, around 100 hairs will be taken from near the crown of your head. Washing, dyeing, or styling your hair with products will have no effect on the accuracy of the test.


So, you’ve got a drug test coming up and you’re feeling uneasy. Don’t get defeated! Here’s how you can try and beat it.


This may seem obvious, but the first thing you should do if you have a drug test coming up is stop using weed. The aim here is to purge any trace of THC or its metabolites as thoroughly as possible. The longer you cease smoking beforehand, the more likely you are to pass the test. Depending on the type of test and your smoking habits, you may need to take a longer break to fully flush your system.


Speaking of flushing your system, there’s nothing better than good ol’ H₂O. Of course, drinking water is most effective for passing urine tests. Luckily, that’s the most common type of test.

To help cleanse your system, pee as much as you can 24–48 hours before your test. Keep hydrating on the day of your drug test. The goal is to dilute your urine, making it harder to detect any residual metabolites.

Just don’t overdo it. Drinking too much water will result in an obviously diluted sample, potentially leading to a retest or increased suspicion. You need to drink plenty of water, but not so much that it becomes obvious. This is indeed a balancing act.


A 2011 study [6] found that zinc is an effective urinary adulterant, with the potential to produce a false negative test result. Research suggests that oral consumption of zinc supplements after light cannabis use could interfere with detection of THC metabolites in urine for between 12 and 18 hours.

Zinc supplements are widely available over the counter in pharmacies and health food stores. So, if a drug test gets sprung on you or you need some extra assurance, you might want to swing by the vitamin aisle. Just make sure to check with your doctor or pharmacist first if you take any regular medications.


If you want to kick it up a notch from water, try a detox drink. Detox drinks work on the premise of expelling or masking the presence of THC and its metabolites. Many of them use diuretic substances to make sure you are passing urine frequently.

Consumer detox products can be quite expensive. If you don’t have the cash, focus on simple detox drinks you can make at home, like coffee or cranberry juice.


Another method to prepare your body for a drug test is activated charcoal. Charcoal is often used to medically manage overdoses; it binds to different substances and helps the body eliminate them. That’s because charcoal molecules have a negative electrical charge; they bind with positively charged molecules in different drugs, trapping them.

The binding process works with THC metabolites. THC metabolites circulate many times through your system via a process known as “enterohepatic recirculation”. They move from blood to liver to bile and into the intestines, before being reabsorbed back into the bloodstream. The cycle then repeats, with a portion of the metabolites excreted as waste each time. Eventually, after many cycles, all metabolites are flushed from your system.

Research [7] shows that activated charcoal binds to metabolites like THC-COOH and THC-COO-glucuronide, preventing their reabsorption into the bloodstream and speeding up their elimination. That means charcoal could help you pass a drug test faster.


So, what’s the best way to take activated charcoal? Thanks to its purifying properties, charcoal has gained popularity as an addition to cosmetics, health products, and even food. The simplest way to take it is via capsules. But, let’s be honest, it’s more fun to do a little baking! The recipe below for charcoal bread results in a unique, black loaf that looks badass and still tastes great.

Please note that you should be careful when ingesting activated charcoal—it could interfere with absorption of medications and vitamins. If you have concerns or take regular meds, check with your doctor or pharmacist before trying it.


This gothic dough will turn any sandwich into a conversation piece.


• 240g plain flour
• 7g dried yeast
• 50g caster sugar
• ½ tsp. salt
• 2 tsp. activated charcoal powder
• 140ml warm water
• 30g butter


• Large bowl
• Cutting board/breadboard
• Bread tin
• Kitchen towel
• Roasting tray
• Wooden spoon


1. Preheat the oven to 200°C. Add flour, yeast, sugar, salt, and charcoal powder into a large bowl and mix thoroughly.

2. Add water to the bowl and continue to mix until the mixture becomes dough.

3. Sprinkle flour over a breadboard and knead the dough whilst adding the butter one small piece at a time. Knead until all of the butter has merged with the dough and it becomes soft and stretchy.

4. Add the dough to a greased bread tin and cover with a damp kitchen towel. Place a roasting tray underneath the bread tin and pour boiling water into it. Place tin and tray into the oven. Return 30 minutes later to add more boiling water.

5. Once another 30 minutes have elapsed (1 hour total), carefully separate the roasting tray from the bread tin and bake alone in the oven for a final 15 minutes.

6. Remove the bread from the oven and allow it to cool.


Here’s a quick recap of the main points:

THC gets broken down into metabolites like THC-COOH by the liver, and this is what many drug tests look for.
Different drug tests have different detection times, which are also influenced by body fat, metabolism, and how much/how often you use cannabis.
Urine tests are by far the most popular method, especially among employers.
If you have a drug test coming up, you should stop using weed immediately.
To speed up excretion of THC or to help mask its presence, drink lots of water (but not too much!).
You can also try: zinc, detox drinks, and activated charcoal.

Ultimately, there’s no fool-proof formula to flush THC out of your system quickly. There are just too many variables. But, that doesn’t mean you’re powerless. Research shows that the methods we discussed could help speed up the process. With knowledge on your side, and a little bit of luck, you’ll be flying high in your free time and nobody will be the wiser. Because, let’s be honest, it’s nobody’s business.

Drug tests are a stoner's worst nightmare, and can mess with even casual users' lives. Here are some tips and tricks to help you beat the THC heat.

World’s Ultimate Guide to Passing Any Drug Test (Urine, Blood, Saliva, Hair)

In this article, you will learn everything you need to know when it comes to passing a urine drug test. Whether you have marijuana in your system or any other sort of drug, these legal and safe recommendations will help you pass all sorts of drug tests.

You are going to learn about effective methods that will help you before your drug test. You will also learn about the factors that can hinder your plans in order to get clean.

If you ever need to jump to a certain topic, be sure to use the Search by Category menu below, located on all of our pages for quick navigation:

Table of Contents

Overall Factors that can have an Impact on Test Results

First, let’s learn what the major factors are when it comes to passing a drug test.

Frequency of Substance Use

This is quite simple to understand. The more you use, the substance will continue to build up in your system, and the more likely it is that you will fail your drug test. Both the amount and the frequency of you using the drugs will play a role in the final results of your drug test.

Total Amount of Body Fat on Your Body

As you may know, THC is stored inside fat cells. When creating our drug test calculator (link below), it was determined that the amount of body fat you have is more important than how much you actually weigh. The more fat cells that are in your body, the more metabolites it will be able to store, and the longer it will take to pass a drug test.

Your Metabolism and Health

The metabolic process ends up breaking down everything that enters your body. Hence, a higher metabolism will break down and eliminate the drugs a lot faster from one’s system as compared to someone who has a slower metabolism. Moreover, genetic makeup, gender, age, and how active you are also affect this process. Plus, according to some evidence, there are specific foods that can also alter one’s metabolism and this can affect the detection of drugs in one’s body.

Passing Probability Calculator

Use the world’s only data-driven marijuana drug test passing probability calculator in order to determine your odds of passing a urine drug test. With over a decade of research and development, this is the only application that can provide an accurate answer to how long cannabis can be detected in your system:

The calculator graphs your Passing Probabilities vs. Days for untampered and diluted/detoxed urine. View Patent US 13/866,015 for more information.

How Urine Drug Testing is Conducted

You would have to submit a urine sample and it will then be sent to the lab, where it is going to be tested using different methods for any signs of drugs in your system. Your sample needs to clear the immunoassay test and in order to do that you should have very low concentration of THC and its metabolites in your urine. The national cutoff for testing THC metabolites is 50ng/mL of urine.

Several Methods to Pass a Urine Drug Test

Permanent Detoxification and Removal of THC Metabolites

This method will remove all of the THC and its metabolites from your body; hence less metabolites will be present in the urine. You will be permanently detoxified until you use weed again. In this method, you need to regularly exercise and have a good diet for a couple of weeks. You can also use additional supplements in order to help with the detox process. This method is perfect for someone who has more time before their test and is looking to completely remove THC from their system.

Temporarily Flushing Marijuana Metabolites from Your Bladder

This method requires the user to drink large quantities of water in order to urinate and flush out all of the THC metabolites from their bladder. This will temporarily reduce the THC metabolites from the body. You need to take in electrolytes and vitamins in order to affect the other important factors, like color, specific gravity, creatinine levels, etc. This method is ideal for the ones who aren’t planning on stopping to smoke anytime soon and need a quick solution before their test.

Substituting a Different Urine Sample that’s not Yours

You can get someone else’s urine or use synthetic urine in order to get a sample that’s 100% clean. You might need additional devices, such as hand warmers or a whizzinator. It should be noted that this method is not legal and we do not recommend it.

What to do when Providing a Urine Sample

Aspirin and a Dilution Process

This is the standard method to use before every drug test, especially when using detox products. You will need to increase your water intake in order to reduce the THC metabolites to undetectable levels. This method can be used when you don’t have enough time and you need an immediate solution a day before your test. However, there’s always a possibility that you will still fail—as no process can be guaranteed.

Things You Need:
  • Aspirin
  • Fluids containing electrolytes (like Gatorade)
  • Creatine powder supplement
  • Vitamin B-12 complex
What to Do:

Take an at-home test first thing in the morning and see if you pass. If you fail your at-home test, it will be imperative at adhere to these directions. If you pass your at-home test, be sure to follow these recommendations anyway—it is rare, but sometimes people fail the lab test right after passing a home test.

It has been found that aspirin may have an impact on the initial immunoassay drug test that urine goes through, causing false-negative results. Fluids that contain electrolytes and creatine will help keep the pH and specific gravity of your urine within range which diluting.

Standard Steps for Dilution:

Step 1) Four hours before your test, take a serving of creatine powder with a glass of water

Step 2) With the same glass of water, take a couple of aspirin pills and a Vitamin B supplement

Step 3) Over the course of the next four hours, try to drink a gallon of fluids with electrolytes

Use a Marijuana Detox Kit

These products are designed to help your body rid toxins through a natural detoxification process, and will help increase your odds of passing a urine drug test.

Substituting Your Urine

Use Your Friend’s Urine

This may be a last resort for some, but it’s the easiest way to pass a urine drug test. Although same gender urine is recommended, you can use either so long as that person wasn’t using anything that could cause you to fail a drug test.

What to Do:
  1. Use a bottle to collect your friend’s clean urine.
  2. Your friend should provide their urine right before your test since it needs to be a specific temperature (if you can’t use previously-stored urine).
  3. Use a heating pad to keep the urine warm enough.
  4. Keep the bottle close to the genital region while it’s inside your underpants.
  5. Transfer at least 30mL of fluid into the sample cup.

Synthetic Urine

This is fake urine that is used by people in order to pass their drug tests and it contains the same ingredients as the real thing. Plus, it smells and looks the same as well.

What to Do:

These products come in both liquid and powder form. If in a powder form, it needs to be turned into a mixture, and then follow the rest of the instructions below:

  1. Add water to the powder and get it to the ideal temperature using a microwave.
  2. Attach the sample to the heating pad.
  3. Hide the sample on your body and bring at least 30ml of the prepared mixture.
  4. Transfer at least 30mL of fluid into the sample cup.

You will need to safely get it inside the test center’s bathroom, and you can do that by either placing the container into a pocket, attach it to your belt, or tape it on the inside of the thigh.


The main component of marijuana is THC, which is fat-soluble. Therefore, it is stored inside the fat cells of the body. The detoxification process comprises of excreting the THC that’s stored in the body fat and releasing it from the body through urine.

Natural detox can take a long time, like a couple of weeks to a few months, depending on the individual’s body, their use of marijuana, and their weight. In order to naturally detox your body, you need to follow a proper exercise and diet program.


  • Get some exercise in order get rid of toxins from your body! Particularly, cardiovascular exercises, like running, walking, jogging, etc.
  • Avoid red meat and junk food, since it’s filled with calories and they can result in storing more fat in the body, which means more storage for THC.
  • Drinking lemon juice in warm water is going to improve digestion and metabolism rate.
  • Adding fruits and vegetables, like leafy greens, will fill you up without adding extra calories.
  • Drinking at least two liters of water on a daily basis will help suppress appetite and help the body metabolize fat.
  • Incorporate more fiber-filled food into your diet, like kidney beans, nuts, black beans, peanuts, wheat bread, etc. It will keep you fuller for much longer.

Have Five or More Days to Naturally Detox?

Use our detox menu below to select a suitable product. All detox products sponsored are safe and will increase your odds of passing a drug test.

Best Recommendations to Pass Your Urine Drug Test

  • A week before your test, stay away from eating greasy and junk food. Have a clean diet filled with healthy foods.
  • Urinate as much as you can by drinking a lot of water. However, don’t go overboard since this could raise suspicions.
  • At least two days before your test, start to drink more water throughout your day as it will help in detoxifying your body. Drink at least 16-ounces glasses four times in a day.
  • Do not drink or smoke no matter how nervous you are. You don’t want to ruin your chances of passing your test.
  • Start exercising a week prior to the test in order to speed up the metabolism. Make sure to stop one day before the test.
  • Avoid toxins and stay away from anything that can expose you to them for at least two days before your test.
  • Use a home testing kit in order to confirm that you are getting the desired results. Hence, you won’t be as nervous on the actual test day.
  • If you are allowed to pick the time for your test then take it in the afternoon, since at that time the urine isn’t as concentrated.
  • Avoid medications or supplements. If you take prescribed medication then take it with you to the test center. However, don’t reveal them unless the people there ask.
  • Try to stay calm during your test and take a couple of deep breaths. It will look suspicious if you’re nervous around the technicians at the test center.
  • On your test day, eat a large meal beforehand and make sure to at least dilute your urine.

Likelihood of Being Drug Tested by Ethnicity


In this article, we discussed several ways to increase your odds of passing a marijuana drug test.

The standard method to use when it comes to providing a urine sample is to dilute your urine with aspirin, electrolytes, and Vitamin B. When using a detox product, always include the dilution process to increase your odds of passing a drug test.

When substituting your urine with something else, make sure the mixture is at the right temperature, hide it on your body with a hand warmer pad, and transfer at least 30mL of fluid into the collector cup.

Follow our recommendations in order to detox naturally and avoid taking anything that can compromise the results of your test.

Use our Marijuana Drug Test Calculator to find out when you'll pass a drug test and learn how to prepare, dilute, and detox your body to increase your odds.