Some people medicating with CBD are subject to workplace drug testing. The intent of such testing is to assure that people don’t work while under the influence of intoxicating drugs. This works well for drugs that are water soluble. Drugs like cocaine and heroin wash out of your system within 2-4 days. LabCorp reports that THC is detectable for 2-7 days after a single use and 1-2 months after chronic use. 1. This puts people who use medical cannabis (hemp or marijuana) at a disadvantage.

Urine drug testing is usually a two step process. The first step is an inexpensive immunoassay test. Immunoassays measure the formation of antibody-antigen complexes. They can produce false positives. If you test positive for THC you will usually then be given a more-expensive gas chromatography test that can tell more precisely what is in your urine.

People taking CBD isolate should not test positive on any urine drug screen. If your job has a strict policy and tests frequently then you should probably only take CBD isolate. Multiple studies have found that CBD isolate works, but that the dose needs to be very precise. CBD that is accompanied by other substances naturally found in cannabis works over a much wider dose range.

The image to the right shows the results of a $1.00 home urine drug test (Easy@home brand from Amazon) that uses the same technology as the initial tests used in many workplaces. If no bar at all shows up next to the “T” then it is considered a positive test. Any bar at all is supposed to represent a negative test. The example shown is the result when I was using CBD isolate supplemented by a small amount of CBD hemp flower twice a week. It’s technically negative, but the lower band is awfully weak. That’s probably because hemp flower contains THC-A that converts to THC when smoked or vaped. This is in addition to the small amount of THC that is usually in flower.If it is essential that you pass urine drug tests then you should probably avoid hemp flower.

It’s comforting to know that I currently test “negative” for THC, but I’m not confident that every lab technician would read this as a negative result (even though they should). To the left is an example of the instructions for a different brand of test that uses the same technology.

Should you test at home? You shouldn’t need to if your job doesn’t test, or if you only use CBD isolate products. If your job tests, and you use full spectrum hemp products, (even hemp oil from places like Amazon that don’t explicitly list CBD as an ingredient) you should consider testing yourself from time-to-time.

1. https://www.labcorpsolutions.com/images/Drugs_of_Abuse_Reference_Guide_Flyer_3166.pdf