2. Tonic Water
That’s right, your typical shelf variety of tonic water that you may want to mix with your gin or vodka can trigger a false positive on a drug test. The original purpose of tonic water was to deliver quinine, a drug that battled malaria, according to LiveScience. That drug still exists in today’s more diluted tonics.
An abstract posted the U.S. National Library of Medicine notes that the presence of quinine in urine “may be evidence of illicit drug use” but that it may also only be from consuming otherwise harmless tonic water. Quinine is listed on the TOXNET data network of toxic substances, used to fight disease and also to flavor carbonated beverages.