Hair Drug Test

While the test is often called a hair follicle test, it is not actually the root itself that is tested, the hair is never plucked. It is cut as close to the scalp as possible or from the arms or legs if you don’t have enough hair on your head. Hair drug testing uses the first inch and a half of growth from the base and roughly 120 strands, to determine any drug use within the past approximately 7 to 90 days.
 

• Hair testing can detect drugs up to 90 days after use.
• They’re nearly impossible to cheat.
• Shampoos can’t mask a drug’s presence in your hair.
• Secondhand smoke does not lead to a positive hair test.

A standard 90-day hair test requires a donor to provide a sample that is 1.5 inches long. If a donor shaves their head prior to the test, a screening facility can perform the test with body hair. The body hair test can go back twice as far as a test with head hair and determine the person’s drug use during that time. If no hair is available, a urine test is the only way to screen that person.