If you’re facing a hair follicle drug test, you’re likely wondering just how far back it can see. Unlike other testing methods, a hair test provides a much longer detection window, which can feel a bit daunting. The question of how long THC stays in your hair isn’t as simple as a number of days; it’s a complex process influenced by your body’s own chemistry.
When you consume cannabis, THC and its metabolites enter your bloodstream. As your blood circulates, these compounds are delivered to the hair follicles. They then become trapped inside the growing hair strand, creating a permanent record of use. Because hair grows at a relatively steady rate, this provides a timeline of your consumption.
The Typical Detection Window for THC
For a standard 1.5-inch hair sample, which is what most tests use, the detection period is typically about 90 days, or three months. This is because body hair grows, on average, about half an inch per month. So, a 1.5-inch sample represents roughly the last 90 days of growth. It’s important to remember that this is a general guideline, and the exact timeframe can vary from person to person.
Factors That Influence How Long THC Stays in Your Hair
Not everyone will process and eliminate THC at the same rate. Several personal factors can affect how long it remains detectable in your hair. These include your metabolism, how often you use cannabis, and the potency of the products you consume. Your hair color and type can even play a small role, as different hair structures may bind to substances differently.
What to Know About Hair Detox and Shampoos
You may see products marketed as “hair detox shampoos” that claim to remove drug metabolites. While some people report success with these, their effectiveness is not scientifically guaranteed. These shampoos often work by aggressively stripping the hair of natural oils and attempting to break down the metabolites on the surface. If you choose this route, it requires careful and precise use according to the instructions.
A Final Thought on Hair Follicle Testing
Hair follicle tests offer a long look-back period, making them a unique challenge. The 90-day window is a good rule of thumb, but your individual experience may differ. If you have an upcoming test, knowing how this process works is the first step in understanding your situation.