Types of Drug Tests

Urine testing

Urine testing or urinalysis testing is the most common form of drug toxicology test used in the US owing to its ease of use, noninvasive administration, low cost, and high accuracy. 10 or 15-panel urine tests can detect a wide range of drug metabolites such as THC (marijuana), amphetamines, opioids, steroids, alcohol, and cocaine. Urine tests are commonly used in pre-employment drug tests.

The immunoassay (the agent in urine tests that screens for substances) will be able to detect the presence of specific drugs in the system if they are above the cutoff threshold. This means that if traces of substances are in urine but are below the threshold, the test will yield a negative result. 

If using a urine test to screen for a specific drug, a more specific screening process may be used, such as liquid chromatography, chromatography, or mass spectrometry. 

Hair follicle testing

Hair follicle testing is often used to determine long-term drug use. Drug metabolites will cling to hair follicles and will remain there for up to 90 days. Metabolites detected near the tip of the follicle determine use was longer ago than those found at the scalp. Hair testing is preferred for offering a semi-permanent record of drug use and because it is difficult to tamper with or influence results.

Blood testing

Blood drug tests boast the highest accuracy of all drug tests. Despite their precise nature, blood tests are rarely used outside of medical settings due to their invasive nature and short time frame for accurate detection.

Saliva testing

Saliva testing (oral fluid testing) can offer accurate results for drug detection of specific substances within a short time frame (often no more than 48 hours). However, they are not commonly used for random screening as they don’t detect certain metabolites such as THC.

Sweat testing 

Sweat testing for drugs is done through the application of a patch to the upper arm, lower back, or midriff that collects sweat over a period of time and detects drug metabolites. Environmental contaminants cannot get through the film, and the adhesive cannot be reapplied once removed to prevent tampering. 

Residue testing

Residue testing is typically performed as part of a home testing kit or at airports. Home test kits typically come with a swab that can be wiped on belongings to pick up drug residue. The downside of these tests is that they can not identify direct use, as any drug residue may have ended up on a person's belongings without them knowing.

Breath testing

Breath testing is performed via a breathalyzer, a handheld device that can detect blood alcohol volume via molecules in the breath. This type of test is typically only used by police and other law officials when pulling over people who have committed a driving offense and who are suspected of being drunk (DWI). They can also be installed in cars as immobilizing devices, meaning the car will not start if alcohol is detected in them.