Saliva drug tests detect most drugs as far back as 24 to 48 hours, while identifying the presence of drugs within 30 to 60 minutes after ingestion, according to Omega Laboratories. While urine testing typically features a 24- to 72-hour window of detection, saliva tests may recognize usage missed by such tests and are less prone to dilution tactics employed to defeat urine screenings.
Employers and the court system commonly use saliva testing to screen for abuse of drugs, including amphetamines, cocaine, opiates and marijuana, states the U.S. National Library of Medicine. Additional substances tested for include oxycodone, barbiturates, methadone and benzodiazepines, notes Omega Laboratories.
Contamination from food and other debris and attempts to stimulate production of oral fluid can affect saliva test results. Citric acid candy and chewing gum are especially potent at stimulating fluid production, effectively changing the pH and concentration of substances in saliva. Such agents have been known to lower the concentration of certain drugs in saliva, such as codeine or cocaine, by as much six-fold in some cases, reports the U.S. National Library of Medicine.
Since over-the-counter medications have also been known to create false positives, samples that test positive are always confirmed using additional screening techniques, explains Omega Laboratories. In most instances, the typical turnaround time is one to three business days after the laboratory receives the sample.