How Long Marijuana Can Stay in Your System

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Your resume looks great. You’ve spent weeks scouring the San Diego job listings and hitting the pavement in your job search. You’ve networked. You’ve spit-shined your shoes and ironed your best shirt. You’ve done everything a job seeker is supposed to do, and finally, it pays off. You get an interview and nail it. The next day, the call comes. You’re hired! There’s just one condition, one last minor thing to get out of the way before the job is officially yours: a drug test.

You’re pretty sure you’ll be ok. You’ve never done anything but smoke weed, and the last time was ten days ago. You’ve heard THC only stays in your system for a few days. So you agree to the test.

You fail it. Someone else gets the job. You’re back at square one in your job search.

How does THC testing work, anyway?

Most often, employers use urine testing to screen for drugs. It may come as a surprise, but urine tests don’t actually detect THC in your body. They screen instead for THC-COOH, a metabolite produced when your liver breaks down THC. This metabolite stays in your system even longer than the THC.  

Most drug screening companies use 50 ng/mL as the common cut-off point for a negative test result; so anything 51 ng/mL and over will come up positive. Although it’s less common, some companies will use a cut-off as low as 20 ng/mL or as high as 100 ng/mL.

So how long will it be before you get a negative test result?

The truth is, there is no single answer to this question. It’s different for each person.

There are some factors that can suggest longer or shorter lengths of time, but it’s important to remember that there are always exceptions.

Metabolism – Everyone metabolizes at different rates. As a general rule, if you have a low metabolism, you will test positive for a longer period of time than someone with a higher metabolism.  

Amount of marijuana consumed – If you consume more marijuana in a given time period than another person with a similar metabolism, it will likely take you longer to get a negative test result.  

Frequency - Average first-time and occasional cannabis users can expect a negative test result 4 to 5 days after consumption of marijuana. The average frequent user can expect to wait at least 10 days for a negative test result. But studies have shown that some chronic marijuana users can test positive for as many as 46 days after consumption – and it can take a full 77 days to drop below the cut-off for 10 consecutive days.  

Why do so many employers do drug tests?

Despite changing regulations around marijuana use here in California, many businesses are remaining strict with their drug-free policies. Some job listings even warn applicants not to bother applying if they are not drug-free or if they carry medical marijuana cards.

Marijuana advocates claim it is unfair that a heavy drinker can go into work having gotten smashed the night before and receive zero penalty, whereas a marijuana smoker can be fired – or not land a job – for smoking even weeks prior.  

Regardless of how marijuana advocates feel, many employers maintain their zero-tolerance policies, and there are a number of reasons this isn’t likely to change any time soon.

  • Drug testing is federally required in some transportation and safety-sensitive industries.
  • Many states offer discounts on workers’ compensation insurance premiums for employers if they take steps to maintain drug-free environments.
  • An employer can be found legally liable if an intoxicated employee harms someone on the job.
  • Employees who use drugs are more likely to be late, to be involved in accidents, and to file workplace compensation claims.

So what now?

These days, even if you’re willing to show up early, work hard, and stay late, it can be difficult to land a decent job that pays the bills. Worrying about lost job opportunities because of failed drug tests only adds to the stress. If you’ve tried and failed to stop smoking marijuana despite the effect it’s having on your life, you might have an addiction and should seek help.