What Your Hair Says about You in a Drug Test

By Michelle Hopkins | 06/03/2019

You can cut it, crop it, and crimp it, and no matter how good you make your hair look, it will talk very candidly about you in a drug test. That’s because hair follicle testing is an accurate, efficient way to detect the use of illicit drugs or misuse of prescription drugs.

In 2018, the Society for Human Resource Management reported that hair follicle testing is used by fewer than 10 percent of employers, somewhat less than saliva and far in arrears of urine testing, the dominant workplace drug screening method. Hair follicle testing is gaining in popularity, though.

Five Facts for Employers to Remember

  1. State and federal laws, as well as industry regulations can differ in what they allow and require related to any drug screening, not just hair follicle testing. You need to stay abreast of current laws and regulations, or work with a knowledgeable occupational health provider to ensure compliance. The only drug test method approved for workplaces covered by federal guidelines is urinalysis (not hair follicle testing).
  2. A hair follicle test can detect:
    • Marijuana
    • Amphetamines, including methamphetamines
    • Cocaine
    • Opiates
    • Phencyclidine (PCP)
  3. Hair drug testing is a two-step process once the specimen is taken from close to the scalp and sent to a SAMHSA-certified laboratory. (SAMHSA is Substance Abuse and Mental Health Services Administration.) At the lab, an ELISA test, or enzyme-linked immunosorbent assay, provides rapid screening. A positive test leads to a second step to confirm the results; that is a gas chromatography-mass spectrometry (GC-MS) test.
  4. Hair follicle testing can detect drug use within the last three months. 
  5. Every individual is different, so hair follicle testing is not 100 percent accurate. While shampoos and styling products aren’t seen as affecting test results, how much a person sweats, skin pigmentation, amount of drug use, and hair bleach may affect drug concentrations.

What Drug Users Hate/Like about Hair Follicle Testing

Hair follicle testing has a bigger window of time than other testing methods for detecting regular use of drugs like cocaine, opiates, and methamphetamines, according to the chief medical officer of a California background screening company. That’s valuable for employers who use non-regulated drug tests for pre-employment, random screening, post-accident, and reasonable suspicion testing. Regular drug users may hate this.

If an individual is an infrequent or first-time drug user, a hair follicle test may not detect drug use a few days before the test because it takes time for hair to grow. Employers need to weigh that fact into their choice of a drug test method. This test could be a reprieve for a sporadic or one-time user, however.

How Is Hair Follicle Testing Used for People with No Hair?

If a person is bald or has a shaved head, a body hair sample can be collected, usually from the arm or leg. If that is not possible, another method of drug testing is needed.

Can Someone Cheat a Hair Follicle Test?

It is virtually impossible.