Skip to content
Includes Expert Content
False Positive for THC
hearts03 posted:
I have been recently taking regular drug tests for work. My first 2 were completely clean then all of a sudden they say I failed and two days later I passed!! I know for a fact that I haven't been using or even around it. How would my levels be so high. I've been reading that Ibeuprofen can cause a false positive. I explained this to my case worker and she said I would need it in writing from a medical doctor. How do I go about getting that. Apparently the lab that tests goes by the creatine (protine) in your system. Now mind you my first two tests showed a level of the protine at about 26.4 but the test that I failed showed about 250+ and then the test that I took two days later and passed showed a level of like 83. Now I take ibeuprofen like candy when I have a migraine, is this possible?
Betty Ford Center
James Golden, MD responded:
Depending on the substance you are referring to, the current urine drug testing methods can tweak out interfering substances (like ibuprofen) as a culprit as a positive urine drug test when the specimen is then submitted for a confirmatory test.

Parameters such as urine creatanine, specific gravity and ph are measured so the medical review officer can know for sure that the urine specimen is a valid one.

Some substances (like cannabis) can remain in the fat stores and come out from time to time in previously heavy users. It may take a long time for the urine to become completely clean on a consistent basis.

You can optimize your outcome by being honest and reporting all prescription and non-prescription drug use when you test and have honest heart-to-heart discussions with your case worker and even your medical review officer.

Lastly, taking ibuprofen like candy for your migraine headaches does not sound like a good idea to me. In fact, this could make your headache worse. I'd suggest you speak with your doctor about this.
hearts03 replied to James Golden, MD's response:
Thank you for your feed back. I have been completely honest with my case worker but this drug testing is being done to keep my job and they lady that my case worker has to report to doesn't seem like she believes that I have been clean. My case worker called the testing lab to see if anything other than smoking could have caused it and they told her no which irritates me to no end because I truly haven't. My worry is this will happen again and I will lose my job. I'm at a loss and don't know what else to do to prevent this from happening. I've stopped taking Ibuprofen just to make sure. We are taking every precaution to ensure this doesn't happen but if it is stored as you say and can show up at any time what can I say, do or prove to my employer that I am not smoking and it is just stored THC from all the years of smoking coming out?

Featuring Experts from Betty Ford Center

Harry L. Haroutunian, MD., is an internationally known speaker on the topics of Addictive Disease and its treatment. He is Board Certified in Family M...More

Helpful Tips

SCIENCE OF ADDICTION While contemplating the objects of the senses, a person develops attachment for them. >STEP I: AVOID THE THOUGHT ... More
Was this Helpful?
1 of 1 found this helpful

Related Drug Reviews

  • Drug Name User Reviews

Report Problems With Your Medications to the FDA

FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.