How long does marijuana stay in your hair?
It takes approximately 5 days for marijuana to show up in your hair it can continue to be detectable through a hair drug test for several months. The presence of Marijuana and other drugs in your hair can be understood by this basic principle. Marijuana is ingested in your body and circulates through the blood stream into your blood, urine, saliva, and into the hair follicles via the bloodstream. The drug metabolites that are deposited into your hair follicle are entrapped in the hair shaft as it grows out from your hair follicle. The average growth rate for hair is approximately .5 inches per month. Drug testing labs test for toxin metabolites trapped in the shaft core. Historical drug use can be measured based on the length of your hair sample from your scalp line but a specific timeline of usage is not possible. They cannot tell the difference between THC metabolites introduced two weeks ago from metabolites introduced two days ago.