Medically reviewed by Katherine Golden, RN
Written by Denise Gonzalez-Walker

Thirty-three states have legalized medical marijuana, with 11 of those states also legalizing adult-use (recreational) marijuana as of October 2020. Come November, those numbers are likely to grow as five additional states vote on either medical or adult-use cannabis initiatives.

But just because marijuana is legal in your state doesn’t mean that you’re protected, should you fail a workplace drug test.

Also, the proliferation of CBD hemp products has raised questions about whether the minimal, non-intoxicating amounts of THC contained in full-spectrum CBD hemp might trigger a positive drug test result.

We hear these concerns frequently enough on the hotline that we decided to take a closer look at current workplace drug testing protocols to help you choose the best course of action for your own use of CBD hemp or legal marijuana containing higher amounts of THC.

Notepad with the word ‘why’ written on the page

Why Does Cannabis Stay in Your System Longer than Other Drugs?

Many people use cannabis to help manage health conditions, boost wellness or simply to unwind after a stressful day. Cannabis’s intoxicating effects generally fade away after 2-8 hours, depending on your mode of ingestion. This means that the bowl you smoked on a Friday evening will be a distant memory by the time you return to work on Monday.

However, when the cannabinoid tetrahydrocannabinol (THC) is broken down, it creates non-active metabolites (THC-COOH) that stay in your system much longer. While these non-active metabolites don’t give you any kind of psychoactive effect, they are the “evidence” of cannabis use that urine drug tests look for. Depending on how frequently you use cannabis, these metabolites can be detected for several weeks or even months.

Other drugs like cocaine, amphetamines and opiates flush out of the body much faster, within a matter of 1-4 days. Alcohol also quickly exits the system, often within hours.

Why is cannabis different? Cannabinoids like THC are fat-soluble, with their non-active metabolites accumulating in fat cells. These metabolites are slowly flushed out via urine over a longer timeframe when compared to water-soluble substances that pass through without making a stop in fat cells.

When thinking about workplace drug testing, it doesn’t seem fair that someone could either lose a job or an offer due to a positive cannabis drug test, especially in a state where their cannabis use is fully legal and very likely happened off the clock. But until employers change their policies or the laws change, drug testing will be a reality for many workers, including those in the healthcare industry.

Workplace drug/alcohol testing consent form and urine specimen cup

Drug Testing and Cannabis: What Do the Tests Look For?

Most workplace drug tests continue to include marijuana in their drug testing panel, even in legal states. Workplace drug tests, including Department of Transportation (DOT) tests, are typically set to trigger a positive marijuana result at 50 ng/ml.

If you’re required to complete a pre-employment drug screening or workplace testing, you can call the lab in advance to ask how many nanograms they’re testing for. This information will help you anticipate what your results might be, based on your past use of cannabis.

  • For occasional users, metabolite levels in urine may remain above 50 ng/ml for 1-5 days
  • For regular once-a-day users, levels may be detected for 1-3 weeks after discontinuing cannabis
  • For moderate multiple-times-a-day users, levels may be detected 4-6 weeks following discontinuance

Factors that Impact Levels of Cannabis Metabolites in Urine

Your best friend tells you that they only had to stop using cannabis for one week to pass their drug screen. Your use is similar to theirs—so can you assume the same rule applies to you?

Not necessarily!

First of all, product potency plays into how long cannabis metabolites stay in your system. Your friend might be using a very low-dose tincture, while you depend on a product with ten times the amount of THC. Ingesting more THC means that you’ll end up with more metabolites which take longer to flush out of your system.

Also, body fat levels may impact how long THC-COOH remains present since it’s stored in fat cells. Put bluntly, the more body fat you have, the longer the metabolites might stick around.

CBD (cannabidiol) oil shown with molecular structure diagram. CBD is a different cannabinoid than THC.

Will CBD Hemp Cause a Positive Drug Test Result?

CBD hemp was legalized as part of the 2018 Farm Bill, and full-spectrum hemp (which contains all of the plant cannabinoids) may contain up to 0.3% THC under federal law. That amount of THC is so small that you won’t feel any intoxicating effects from it—but will it show up on a workplace drug test?

That’s an incredibly important question for many people. When your job is on the line, you can’t afford to take chances.

We suggest that anyone who is subject to regular or random drug tests should limit their purchases to CBD isolate products which have all THC removed. (Check out our article on CBD for more information on different types of CBD hemp.)

Be sure to confirm the products are THC-free by reviewing third-party test results, which are called Certificates of Analysis (COAs). All reputable manufacturers will have COAs available for their products. COAs should be on the product website or available by request. Details on the COA will vary, but they should always include results for CBD and THC levels.

We know that COAs can be confusing! Our Leaf nurses are experienced at reading COAs and can help with any questions you may have. Call us at 844-LEAF411 (844-532-3411) or chat us from the Leaf411.org homepage during hotline hours.

Home drug test for THC, with urine specimen cup beside it.

Using Retail Drug Tests as a Tool

Curious whether your cannabis use will register on an employer-mandated drug test? Test yourself and see! Over-the-counter urine drug tests are widely available for home use. They also give you the chance to find your optimal length of time to abstain from cannabis, if you’re anticipating pre-employment drug screening or annual tests in the near future.

Some companies like UTest even offer marijuana drug tests at different sensitivity levels, including 15 ng/mL, 20 ng/mL, and the standard 50 ng/mL, so that you can prepare based on what you know about your workplace’s testing policies. 

Man filling a glass with water at the sink, hydrating to help flush out THC-COOH metabolites before a drug test.

Other Steps to Prepare for a Drug Test

You’ll find all kinds of advice online about how to pass a workplace drug test. Much of it is based on anecdotal evidence or is merely an urban legend. 

However, we do suggest safely increasing your fluid intake prior to a test to help flush out metabolites more quickly. Also, if possible, schedule your drug test later in the day, when drug metabolites will be less concentrated in urine.

Our Leaf Nurses Are Ready to Help

Our fully-licensed registered nurses answer all sorts of cannabis and CBD hemp questions on the hotline. Whether you’re concerned about workplace drug tests or simply curious about trying cannabis for pain, insomnia or other health concerns, we’re here to help at no cost to you! Call us at 844-LEAF411 (844-532-3411) or chat us from the Leaf411.org homepage during hotline hours.