As a healthcare professional, a common question that I receive when talking to patients and clients who are interested in incorporating the use of hemp products or hemp foods into their daily routine is:
Hemp-based foods and hemp body products commercially produced and sold in the United States are not legally allowed to contain the potentially psychoactive cannabinoid known as THC (Delta-9 Tetrahydrocannabinol). If a laboratory-tested hemp product did happen to contain trace amounts of this compound, it would be in such small quantities that it would likely require exorbitant amounts of ingestion or use for it to even remotely begin to show up in the smallest amount on a drug test.
“Will eating hemp foods show up positive for THC on a drug test?”
According to the research studies available, the answer to this is question is a resounding NO! Regular consumption or use of commercially made hemp foods (such as seeds, cooking oil, cereals, milk, granola) or hemp products (lotions, shampoos, lip balms, etc.) will not show a positive result for THC on a drug test.
However, with that said, consuming non-commercially produced hemp foods, hemp-based oils, or using homemade hemp-based products may have risks to test positive. Non-federally regulated foods and products, like those purchased from a dispensary, farmer’s market, or even products bought online, do not necessarily follow any sort of federal food safety guidelines or food and drug administration regulations. When purchasing these types of hemp products, make sure you use caution and ask questions about how they were made and whether they were tested before being packaged.
The hemp foods contained 4 different doses of THC, with participants consuming each dose for 10 days before testing their urine. THC doses in hemp seed oil ranged from 0.09 mg to 0.6 mg. At the highest dose of 0.6 mg, which is an unrealistically high amount for daily consumption of hemp foods, the highest measured THC-COOH concentration in urine was 5.2 ng/mL, which is well below the GC-MS confirmation threshold of 15 ng/mL. 3 This study shows that it is very unlikely for hemp food consumption to interfere with an immunoassay UDS, or GC-MS.
Q: Can you explain the reason for a false-positive urine drug screen for marijuana?
Another potential source of UDS interference is thought to be the use of non-steroidal anti-inflammatory drugs (NSAIDs). One study evaluated 3 drugs (ibuprofen [Advil, Motrin, others], naproxen [Aleve, Naprosyn, others], and fenoprofen [Nalfon, others]) in patients taking them chronically or acutely. The authors theorized that NSAIDs would interfere with the immunoassay test through interference with the enzyme reaction, production of erroneous absorbance reading, or secretion of an endogenous substance that inhibits cannabinoid binding to an antibody. Of the 510 urine samples collected from 102 participants, 10 samples (0.02%) tested positive for cannabinoids. Follow-up GC-MS tests showed that 8 of the 10 samples (80%) were true positive for cannabinoids. Of the 2 samples that were positive due to NSAID use, one was from acute ibuprofen use (1,200 mg in one day), and the other was from chronic naproxen use (1,000 mg daily for no longer than 30 days). 9 This study shows it is unlikely for NSAIDs to cause a false-positive marijuana UDS.
Passive marijuana inhalation has been thought of as a potential reason for a false-positive marijuana UDS. Three studies were performed to analyze this theory: one with participants exposed to secondhand smoke in a small enclosed room for
1 hour, another study with participants exposed to the smoke daily for 3 consecutive days, and the third study was with participants exposed to smoke in a small, closed station wagon. Eighty different urine samples were analyzed; only 2 samples exceeded the 20 ng/mL threshold used in their immunoassay test—and those just barely. 8
UDS is an immunoassay test that uses antibodies to detect presence of specific drugs or metabolites. It is the most common method for initial screening. Advantages of the immunoassay test include the capability for large-scale screening and rapid detection, but the disadvantage is the potential for false-positive results. 4 A rapid UDS for marijuana is performed using a threshold of 50 ng/mL. 6 If a test comes back positive, a more specific gas chromatography-mass spectrometry (GC-MS) test, which uses a threshold of 15 ng/mL, can be performed to confirm the positive result. 6
The GC-MS test is considered the “gold standard” of confirmatory tests due to its ability to detect small quantities and confirm the presence of a specific drug. Advantages include high accuracy and sensitivity. Disadvantages include the amount of time it takes for the test to be completed, the high expertise level required to perform the test, and the cost of the test. 4
Tetrahydrocannabinol (THC) is the active ingredient of marijuana, however UDS test for the metabolite 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). 3-5 A UDS does not prove there is an exact amount of the metabolite in the urine but indicates the metabolite concentration is above a given theshold.
His company have since taken him back, although the contractor that he failed the test for has refused to accept his return to work.
And if you’re unlucky enough to be breathalysed immediately after eating pizza, then this could cause you to fail the test.
But having a few G&Ts could also liven up your drug test results.
There’s nothing worse than when your dog actually did eat your homework, but you're still not believed.
“It is unlikely that a single poppy seed roll, or even a dozen rolls, would result in an individual ingesting enough morphine to have a pharmacological effect.”