How long does thc stay in your hair?

It may be detected: In hair follicles for months. In “pharmacokinetics of cannabinoids” by mcgilveray ij it is stated “hair tests are more likely to detect regular than occasional marijuana use. One study found that 85% of daily users tested positive for marijuana, versus 52% of occasional smokers (1-5 times per week).

Up to 3 months.: If a regular user, it can still be detected in 3 months.