Incredible How Long Hair Drug Test 2023. Web a hair follicle drug test can detect drug use over the past 90 days. A urine drug test can only detect drug use for several days, while a hair follicle drug test can pick up on drug use as far back as 90.

Web what time period does a hair drug test cover? However, older research notes that these test the oil in skin that transfers to hair, so. By travis andersen globe staff, updated november 16,.