A list of things about as long as your arm. Included are such benign drugs as advil, aleve, Motrin, Bayer Select Pain Relief Formula...basically, go to the pain reliever shelf in the drugstore. Everything on it except aspirin and Tylenol will throw a false positive on a marijuana screen. However, the tests have been refined to recognize these items, and they are ignored. The labs know what to look for. If there is any question, the sample can be reevaluated using more complex methods.

Additional Information

According to Ask Doc Web, the following substances have been known to generate false positives for THC (the active ingredient in marijuana) or marijuana.

Advil - false positive for THC, Marijuana

Aleve - false positive for THC, Marijuana

Anaprox - false positive for THC, Marijuana

Ansaid - false positive for marijuana

Apo-Naproxen - false positive for THC, Marijuana

Atripla - false positive for cannabinoid THC

B2 vitamin - false positive for THC

Bayer Select Pain Relief Formula - false positive for THC, Marijuana

Clinoril - false positive for THC, Marijuana

Cramp End Tablets - false positive for THC, Marijuana

Diabetes - false positives for Amphetamines, Cocaine, THC, Ecstasy, Meth and Opiates

Dolobid - false positive for THC, Marijuana

Dronabinol (Marinol) - false positives for THC

Edecrin - false positive for THC, Marijuana

Efavirenz - false positive for THC, Marijuana

Feldene - false positives for THC

Fenoprofin - false positive for Marijuana, Amphetamines, Barbiturates

Flurbiprofen - false positive for marijuana

Genpril - false positive for THC, Marijuana

Haltran - false positive for THC, Marijuana

Hempseed Oil - false positive for THC

Ibuprin - false positive for marijuana

Ibuprofen - false positive for Marijuana (THC)

Ifenoprofen - false positive for THC, Marijuana

Indocin - false positive for THC, Marijuana

Ketoprofen - false positive for THC

Kidney infection - false positive for Amphetamines, THC, Ecstasy, and Opiates

Liver Disease - false positive for Opiates, Ecstasy, THC and Amphetamines

Marinol® false positive for Marijuana (THC)

Meclomen - false positive for THC, Marijuana

Mediprim - false positive for marijuana

Medipren - false positive for THC, Marijuana

Midol - false positive for THC, Marijuana

Motrin - false positive for THC, Marijuana

Nalfon - false positive for Marijuana, Amphetamines, Barbituates, Benzodiazephines, Methaqualone

Naprosyn - false positive for THC, Marijuana

Naproxen (Aleve) - false positive for THC, Marijuana

Navonaprox - false positive for THC, Marijuana

NSAIDS - false positive for THC, Marijuana

Nuprin - false positive for THC

Orudis KT - false positives for THC

Oxaprozin - false positive for THC, Marijuana, Benzodiazepines

Pamprin® - false positive for THC, Marijuana

Pantoprazole - false positive for THC

Phenergan® - false positive for THC, Methadone

Prescription NSAIDS

Promethazine - false positive for THC

Promethegan - false positive for THC

Proton pump inhibitors - false positive for THC

Protonix - false positive for THC

Relafen - false positive for Marijuana

Riboflavin (vitamin B2) - false positive for THC

Rufin - false positive for THC, Marijuana

Sustiva (Efanirenz) - false positive for THC or Marijuana

Tolectin® - false positive for THC, Marijuana

Voltaren - false positive for THC, Marijuana

It appears that both prescription and over-the-counter NSAIDS (Non-Steroidal Anti-Inflammatory Drugs), such as Advil®, Aleve®, Motrin®, Tylenol®, Pamprin®, Midol®, etc. have all been known to generate false positives for marijuana on drug screens.

Additionally, some medical conditions such as diabetes, kidney infection, and liver disease may result in a false positive.