U.S. flag

An official website of the United States government, Department of Justice.

Evaluation of Saliva/Oral Fluid as an Alternate Drug Testing Specimen

NCJ Number
Date Published
July 2004
75 pages

This study determined whether saliva/oral fluid is a suitable specimen for drug testing in the criminal justice system.


The study consisted of a literature review and a clinical study that used codeine (opiate) as a model drug in assessing the practical problems of collecting and analyzing oral fluid samples. The literature review of 85 articles found that testing for drugs of abuse in saliva can be readily performed; however, more scientific data are needed for a full assessment of the utility of saliva as a testing medium for amphetamines, cannabinoids, and opiates. The advantages of using saliva as the testing medium are that it can be collected easily, noninvasively, and under direct supervision; the saliva-drug concentration should reflect blood-drug concentrations; and saliva is relatively free of blood constituents, so it can be easily processed for testing by conventional drug screening and confirmation methods. The clinical study found that the technique used to collect saliva affected the drug concentration. Nonstimulated spitting was the most effective technique in producing the highest levels of drug concentration. The current method of using a specified concentration of saliva immunoglobulin G was apparently ineffective in determining whether an oral sample had been diluted. More research is required to identify a chemical marker that will ensure the validity of saliva specimens. Future research should also determine how drug concentrations in saliva correlate with drug concentrations in other body fluids, as well as how factors such as pKa, physical size, and the degree of protein-binding lipophilicity affect drug transfer into saliva. 27 tables, 9 figures, and 80 references

Date Published: July 1, 2004