We get a lot of questions from safety managers about hair testing and whether it’s a better option than urine testing.

In this post, we answer the ten most asked questions about hair testing and explain the differences between it and urinalysis.

1. What is hair drug testing?

Instead of relying on bodily fluids, such as urine or saliva, hair testing analyzes the hair shaft to look for the presence of drugs. Unlike body fluids, hair testing resists evasion by adulterating or substituting samples or by simply abstaining from drug use for a few days. Compared with urine testing, hair testing provides a greater number of positives due to its longer detection window.

2. Who uses hair drug testing?

Thousands of companies use hair testing to screen applicants and perform random drug tests on workers.

3. What drugs are included in a standard hair follicle drug test?

Cocaine, marijuana, opiates (including heroin, codeine, morphine, oxycodone, hydrocodone, and hydromorphone), methamphetamine, Ecstasy (MDMA), Eve (MDEA), and phencyclidine (PCP).

4. What time period does a standard test cover?

A standard test of one-and-one-half inches of head hair cut close to the scalp can provide a several month window to detect drug ingestion. Urine tests are only good for two to three days in most cases.

5. How fast does head hair grow?

Studies indicate that hair collected at the crown of the head grows, on average, about a half-inch per month, although that varies among people.

6. Can tests be run on people with little or no hair?

Yes. If an insufficient amount of head hair is available, certain body hair can be used as an alternative.

7. How does hair analysis compare to urinalysis?

The main difference is the wider window of detection with hair. Cocaine, methamphetamine, opiates, and PCP are rapidly excreted and usually undetectable in urine 72 hours after use. Rather than the hours or days covered by a body fluid test, a hair test covers a period of months, ensuring that a drug user cannot evade the test by simply abstaining for a few days.

8. How soon after drug use can a drug be detected in hair?

It takes approximately 5-7 days from the time of drug use for the portion of the hair containing that drug to grow above the scalp.

9. What is the shortest time period that can accurately be evaluated?

In most situations, the minimum time period is approximately one month. A hair test does not determine drugs used on a particular day or week.

10. How effective is hair testing in detecting drug users?

Hair testing is up to 5-10 times more effective in identifying drug users than urinalysis.

Before you enroll in a hair drug testing program or add hair testing to your drug policy, request a free consultation from us. We will answer your questions, explain the advantages of hair testing and advise you on the best policy for your situation.