This work offers a comprehensive review of the science of drug testing in all its aspects, placing emphasis on technologies that use body fluids other than urine for determining the presence of drugs of abuse. The authors discuss the various body fluid specimens suitable for testing for illicit drugs - particularly saliva, sweat, and hair - describe the structural and manufacturing aspects of on-site testing devices based on lateral flow immunoassay, and detail the pitfalls of using these specimens. They also discuss in detail the problem of sample adulteration and its detection. Since oral fluid has the best potential of succeeding urine as the next matrix of choice for drug detection, four popular saliva testing devices are examined: Intercept[registered], the Drager Drug Test[registered], Oratect[registered], and Drugwipe. Political, social, and legal issues are also considered in articles on privacy, the use of drug testing in courts, and the problem of sample adulteration.