• FRS Law Group

    (Flinn, Ruble & Salazar)

    Elgin IL: 224-276-6641
  • FRS Law Group

    (Flinn, Ruble & Salazar)

    Sycamore IL: 630-202-1559
  • Donahue & Walsh, P.C.
    McHenry IL: 815-889-2364
  • Granger & Donahue
    Rockford IL: 779-203-9049
  • Cohen & Donahue
    Palatine IL: 847-452-5124
PI Attorneys of Northern Illinois

A Proven Leader In Illinois Criminal Defense And Real Estate Law

False positive drug tests increase with shifting cannabis laws

Scientists say routine drug testing can easily confuse two substances found in cannabis, one that is legal and one that isn't in most states. The mistaken results have potentially disastrous consequences for people who test positive for the presence of THC.

The chairman of the American Society of Crime Lab Directors expressed concern over labs that might be accidentally mistaking the intoxicating ingredient in marijuana for the legal substance called CBD, which is also found in cannabis.


Hundreds of chemicals found in cannabis can cause drug-like reactions within the body. The two getting the most attention are:

  • THC: Tetrahydrocannabinol is the primary psychoactive ingredient in marijuana and is what makes people feel "high." The chemical binds with other receptors, especially in the brain, controlling mood and pain and can create a euphoric feeling.
  • CBD: Cannabidiol won't get you high, but it can work with other elements in the body linked to well-being and is used to help relieve symptoms for arthritis, Crohn's disease, diabetes and a host of other ailments. CBD became legal in December 2018 as part of the Farm Bill, which legalized hemp.

Standard drug tests can't tell the difference

While CBD causes different reactions in people, its chemical structure has enough in common with THC to produce false positives in common forensic drug tests. As CBD-infused products become more widely available, experts say false positives are likely to increase. In one example, a Florida couple was charged with marijuana possession after a CBD-infused gummy bear tested positive for THC.

Risks will continue, even in states where pot is legal

Illinois is the 11th state to legalize recreational marijuana, and adults 21 and older will be allowed to purchase up to 30 grams starting on Jan. 1, 2020. However, that offers no protection as false positives can still happen for people suspected of "drugged" driving. Drug testing is also allowed for employers, public housing authorities, child service agencies and other entities. If you have been falsely accused of a drug crime, an experienced criminal defense attorney can challenge the accuracy of testing and work to get the charges dropped.

No Comments

Leave a comment
Comment Information

Contact An Experienced Attorney

Se Habla Espanol

Bold labels are required.

Contact Information

The use of the Internet or this form for communication with the firm or any individual member of the firm does not establish an attorney-client relationship. Confidential or time-sensitive information should not be sent through this form.


Privacy Policy

Email Us For A Response

Donahue &
Walsh, P.C.





Granger &

Cohen &

Palatine Office
800 E Northwest Highway
Suite 602
Palatine, IL 60074

Phone: 815-889-2364
Phone: 847-452-5124
Fax: 847-930-1135
Palatine Law Office Map

Elgin Office
2400 Big Timber Road
Suite 108
Elgin, IL 60123

Phone: 815-889-2364
Phone: 224-276-6641
Fax: 847-930-1135
Elgin Law Office Map

McHenry Office
4310 Crystal Lake Road
Suite C-D
McHenry, IL 60050

Phone: 815-322-9678
Phone: 815-889-2364
Fax: 815-344-8922
Map & Directions

Sycamore Office
145 S. Sacramento Street
Sycamore, IL 60178

Phone: 815-322-9678
Phone: 630-202-1559
Fax: 847-930-1135
Sycamore Law Office Map

Rockford Office
One Court Place
Suite 100
Rockford, IL 61101

Phone: 815-322-9678
Phone: 779-203-9049
Fax: 815-329-6768
Rockford Law Office Map