If you are a cannabis user and suddenly find yourself having to take a drug test for weed it can be quite frightening. In many places in the world testing positive for THC can mean losing your job, your medical benefits, insurance, or even your liberty. Because of this, many folks want to find ways to trick the drug tests or provide what’s known as a false negative. Over the years many companies have started selling commercial products to help you pass a urine test, and there is no shortage of home remedies available from a quick internet search.

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In fact, with so many options it is difficult to separate the truth from the fiction. We have put this article together to help you understand how to effectively pass a urine test. The most common form of drug testing today is in the workplace, and the kits used can detect for cannabis for several days after last use, one study found it to be up to one week for single-use, 10-15 days for regular users, and 30+ days for heavy users.

Considerations For Trying To Pass A Urine Test

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Before getting into the ways to trick a urine analysis, we should familiarize yourself with the ways testing agencies protect against such alteration to make sure you know what to be careful about. The groups providing the testing know many of the tricks that are available online and have thus devised countermeasures for most of them. The main technique they use to reduce fraud is to be present and observe the sample being collected.

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This will make it difficult for the person providing the sample to substitute urine or add compounds to the sample. Most likely they will also make you wash your hands, and remove all jackets, long shirts, handbags, and other accessories before providing the sample. You should try to get an idea of their procedure before deciding what technique to use. Also, you should know that there are many testing methods, the cheap and quick kits are generally easier to trick than lab analysis using specialized machinery and multiple testing parameters. 

In both cases mentioned above, once the person testing the sample has obtained it, they will check visually to see if it has been diluted. They will also look to see if it is cloudy, bubbly, dark, or anything else that could indicate it was contaminated or altered. More modern tests go a step further, and will simultaneously check for biological and chemical factors such as pH, creatinine, electrolyte concentrations, and more. Some also test for the presence of adulterants such as those listed below, including bleach, ammonia, commercially available products, and even so called ‘Stealth’ compounds. 

How To Pass A Urine Drug Test

There are many websites claiming to teach you how to pass a urine drug screen (UDS) but there is very little published scientific data on whether or not they actually work. However, there was a systematic review performed in 2007 which analyzed various methods used to trick urine analysis as found on websites such as erowid.com.

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The authors of that study identified over 200 methods to tamper with a urine test, but many were very similar or were just going under different brand names. So, after removing the duplicate methods they ended up with 28 different techniques for passing a drug test. These could further be divided in 3 types:

  • Those which are ingested
  • Those which are added to the urine
  • Those which are a urine substitute.

Substances Consumed To Eliminate THC From Urine

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Most of the substances used to help eliminate THC from urine work to increase the excretion of THC, or to dilute the sample. Many also contain creatinine or protein as not to appear diluted.

Due to ethical considerations, human trials using these products are rare. However, in this study by Jaffee et al. they reviewed several experiments in which different teas and supplements of juices were consumed alongside a gallon of water. The conclusion was that there was no difference between the different teas or herbs, but the primary factor was the gallon of water that was drunk and caused dilution of the sample.

However, it should be noted that dilution is easy to detect by color, protein, and creatinine content and in some cases will require a new test or lead to legal action. Even if you buy commercial products which contain riboflavin or creatinine, this is probably the easiest way to get caught trying to pass a UDS. B vitamins will cause the urine to change to an orange color and will also make the urine fluoresce under a black light, which many labs now check for. 

A 2011 study found that zinc was effective at masking the presence of THC and several other drugs, and was almost impossible for researchers to detect. For workplace drug tests, taking zinc supplements seems to be one of the most effective and difficult to detect methods of tricking a urine analysis.

Compounds Added To The Urine Before Testing (Not for Ingesting!)

  • Glutaraldehydeone of the earliest compounds sold commercially since 1993, different studies yielded different results, with several not identifying THC, and others being able to. It was concluded that the major factors where how much THC was in the sample, and how much glutaraldehyde was used. So, if you are using a commercial product containing glutaraldehyde be sure to use a lot of it.
  • Nitrites – Nitrites are the main ingredient in many commercial products, and were found to be more effective at removing THC from the urine sample than glutaraldehyde for most testing methods. In some cases, 100% of the THC could be eliminated from the sample.
  • Pyridinium chlorochromate (PCC) – Is another commercially available additive that has been proven to fool most urine tests. However, it does reduce the pH of the urine, which some testers do screen for.
  • Peroxidase and peroxide (Stealth) – Stealth is a combination of two compounds which act together to eliminate many different markers of drugs, including THC. The compound works for most screening methods used to analyze urine.
  • Bleach – Bleach is the most effective common household item used to trick urine tests. It works not only for THC, but also for several other drugs. However, it does occasionally cause a false positive for PCP.
  • Vinegar – Vinegar is another household item that is effective at tricking a urine test, however it is easily noticed with a pH test. Remember that some of these compounds, like vinegar, can be seen on gas chromatography tests, so use them at your own risk.
  • Visine – Is an over the counter eye drop which has been in several studies to mask the presence of THC, but not other drugs.
  • Drano (Sodium hydroxide) – has been shown in several studies to mask the presence of THC and other drugs, however, it significantly alters the pH of the urine and in some cases causes crystals to form in the sample. 
  • Soaps – In a bind, some people have resorted to using hand soap to treat urine. While this has been shown in several studies to mask the presence of THC, it has the risk of showing a false positive for other drugs such as benzodiazepines and amphetamines. It is also easily detected visually as it will make the urine bubbly.
  • Sodium Chloride (table salt) – Only a few studies looked at the effectiveness of table salt, and found it around 50% effective for masking THC presence.

Many other household items were also tested, but with very little effect. Things like ibuprofen, hydrogen peroxide, and vitamin B2 all produced some effect, depending on the type of drug test used, but none were effective across most sampling techniques. Keep in mind that nonsteroidal anti-inflammatory drugs (NSAIDS) can sometimes cause false positives for THC. It was also mentioned in the study that none of the herbal products sold online claiming to work had any effect on the tests.

Urine Substitution And Fake Urine

There are two main ways that people use substitute urine to pass a drug test, either by purchasing synthetic urine or obtaining urine from a non-user. The second option is the most ideal, as the only way to detect alteration would be through temperature. Often condoms are used to store the urine, and a small pin is used to puncture it and create a convincing stream into the cup. Cheap hand warmers can also be used to help maintain temperature.

Today, many commercial products are also available, from simple bags containing a valve, to more complex prosthetics that even have electronic temperature controls. Many are difficult to detect even if being observed while urinating. Models are available for both women and men, as well as different skin colors.

So, in conclusion, the best method to pass the test depends on the test being done. If it is a cheap, onsite testing kit, additives or dilution (drinking 1-2 gallons of water before) may work fine. However, if it is lab-based testing then really the safest bet is to substitute urine using a prosthetic device.