If you’ve ever enjoyed an edible, you might have wondered how long it stays in your system, particularly when it comes to your hair. Unlike a blood test that measures recent use, a hair follicle test is designed to look back much further, sometimes up to 90 days. This can be a source of anxiety, especially for a pre-employment screening.
The science behind it is fascinating. When you consume an edible, the active compounds, like THC, are processed by your body and enter your bloodstream. As your blood circulates, these metabolites are deposited into your hair follicles, becoming trapped in the core of the hair strand as it grows. Because hair grows at a relatively consistent rate, it creates a timeline of your substance use.
Why Hair Tests Look Back So Far
Hair follicle tests are unique because they provide a long detection window. While traces of a single edible might show up in your blood or urine for a few days, they can be present in your hair for months. This is because once the metabolites are embedded in the hair shaft, they remain there permanently unless the hair is cut. Standard tests typically analyze the 1.5 inches of hair closest to your scalp, which represents about 90 days of growth.
Factors That Influence Detection in Your Hair
It’s not a one-size-fits-all situation. Several personal factors can affect how long edibles are detectable. Your hair color and type can play a role, as can your metabolism, body mass, and how often you use cannabis. For a one-time or very infrequent user, it’s possible that a single edible might not deposit enough metabolites to be detected. However, for regular consumers, the evidence accumulates clearly in the hair shaft.
What You Can Do About a Hair Test
If you’re facing a hair test, you might be looking for solutions. It’s important to know that typical detox shampoos are often unreliable. Since the test analyzes the hair inside the follicle and the strand itself, surface-level washing isn’t effective. Some people resort to cutting all their hair off, but be aware that if you have no scalp hair, a lab may use body hair instead, which has a different and even longer growth cycle.
In the end, the most straightforward way to pass a hair follicle test is through a period of abstinence. Because of its long detection window, planning ahead is your most reliable strategy. Knowing how these tests work gives you the power to make informed decisions about your consumption and wellness.