Marijuana and drug detox kits

Dear Alice,

I have a question. I read what you wrote about how long marijuana stays in the system. I have smoked every day for the last three months, but have now stopped completely. I am assuming it will stay in my system for three months. I regret this now. I want to look for a job and many firms drug test. I see on the web that there are kits that can be used to help pass the test. Do they work?

Thanks for your advice. I've never smoked before this and never will again!!! Thanks!

Dear Reader,

While drug testing can be done using hair or blood, the most common method used is a urine test. As to your question, there are no real benefits of using most home detox kits to help you pass a drug test, as they generally won't help the marijuana (also commonly called pot or weed) pass out of your system. Fortunately, marijuana will eventually be out of your system, usually by three months as you state, but more often sooner. So before you invest in a test, keep reading for more on drug detoxing!

While most detox kits don’t work, the type of drug test done may determine whether or not you might want to even consider a detox kit in the first place. There are three main ways to test for drugs: through urine, through blood, or with a hair sample. Hair samples and blood tests are on opposite ends of the testing spectrum — hair samples can test drug use within the past three months, but may miss recent use, while blood tests must be done in a shorter time frame from drug use, especially for drugs with a short plasma half-life (the time it takes for the amount of a drug in the body to reduce by half) such as pot. Blood tests are virtually tamper-proof, while hair samples can be affected by anything from the amount a person sweats to whether or not they bleach their hair. Detox kits are typically designed for urine samples, so if they test by blood or hair sample, a detox kit may not be an option.

Urine sample tests are used more often than blood and hair sample tests because the collection is noninvasive but sensitive to cannabis use over time. Urine samples consist of up to two parts: a screening test, which all samples undergo, and a confirmatory test, which is done on samples that don’t test negative, including results that read as invalid. The screening test is an immunoassay, which is a test that uses an antibody to identify the presences of a substance in a solution. It's key to note that the screening test can’t identify the type of drug present, but a confirmatory test can. However, not all antibodies are created equal, so newer synthetic cannabinoids (including ‘spice’ and ‘K2’) aren’t detected by a standard urine drug screen. Urine screening has the ability to produce false positives as well, with the intake of certain medications and other chemicals, so you may want to be wary of what you put into your body in the days leading up to a drug test.

Home detox kits usually consist of adulterants, or chemicals that could invalidate urine sample tests. These are used either through ingestion before producing the urine (called tampering) or through adding the chemical to urine after it has been expelled from the body (called masking). The detox kits that target tampering usually contain a mixture of compounds, such as goldenseal, vinegar, niacin, vitamin C, or herbal teas or powders. Current research suggests that only one of these compounds may speed up the process of eliminating marijuana from the body. The herbal teas were found to decrease marijuana metabolite levels significantly after ingestion of two quarts of fluid. Some kits that target masking may contain compounds that will “trick” the test into a “pass,” but research has found that only table salt and bleach have been shown to have the capacity to produce false negative results for cannabis. People often combine tampering and masking methods, so the success of these methods individually is in question. 

A third way that these kits may work is through urine substitution, either with synthetic urine or somebody else’s urine. Urine integrity tests will usually flag synthetic urine, which doesn’t contain some compounds normally found in human urine, such as cortisol, the stress hormone. A urine integrity test may also check for the presence of salt or bleach, the masking adulterants mentioned previously, and it can also reveal if a urine sample is the wrong temperature, pH, color, or gravity, or if the smell is odd or the urine too diluted. It may be helpful to know that the levels of cannabinoids and their derivatives in urine can fluctuate over time — even over the course of a single day. So while you may pass a drug test on one day, you might fail the next.

Now, here’s the good news: while a urine test can detect regular weed usage up to 100 days after the last use, most individuals (even daily users) no longer have detectable levels of marijuana in their urine within four to six weeks. However, even a single instance of pot use may cause a positive urine drug test from three days up to one week after use. There are a myriad of factors that affect drug metabolism, or the time it takes for your body to break down a drug. The frequency, duration, and strength of the drug are all factors. In terms of testing negative, the type of test used as well as test sensitivity will affect whether or not you pass with flying colors or fail.

At the end of the day, time is really your best bet for passing the test. In the meantime, fine-tune your resume, brush up on those interviewing skills, and work towards your goal of staying smoke free!

Last updated Oct 05, 2018
Originally published Apr 13, 2012

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