False-positive results of Drug Tests
Approximately 30-50% of all positive results are false-positives, which means the test found the presence of illicit drugs but none were taken. Laboratory errors account for some of these errors, but false-positives may be attributed to more than 300 counter medications that can affect the test (see table).
| If you eat: | You could get a possitive result for: |
|---|---|
| Ibuprofen (pain relief) | Marijuana, barbiturates or benzodiazepines |
| Cold remedies | Amphetamine |
| Hay fever remedies | Amphetamine |
| Nasal decongestants | Amphetamine |
| Diet pills | Amphetamine |
| Sleep aids | Barbiturates |
| DHEA | Anabolic steroids |
| Novocaine (used in dentistry) | Cocaine |
| Dietary supplements containing ephedrine | Amphetamine |
| Poppy seeds * | Opiates / morphine |
| Hemp food products ** | Marijuana |
* Large amounts of poppy seeds, for example, a pastry filled with poppy seeds, not a poppy seed bagel, need to be consumed to cause a positive test. However, sophisticated testing can discern the seeds of poppy opiates.
** Hemp oil is eaten for its nutritional benefits.
If you mistakenly found positive for drug use, evaluate whether you have taken any substances known to cause false-positive. Also, remember that the liver problems or diabetes can cause a false positive for amphetamines, opiates or cocaine.
