List Of How Long Do Drugs Last In Hair Follicle Test References. Web many times, it can take between five and seven days for substances to be detectable on a hair follicle drug test. Hair follicle drug testing uses cutoff levels to indicate whether a test is negative.

Web the hair follicle drug test, when using the standard 1.5 inches of hair, can detect previous drug use up to 3 months. This type of test can reveal the presence of drug use for as long as 90 days. Free, easy returns on millions of items.