How much thc is detectable in a hair follicle drug test?

Longest window of de: Hair test offers the longest window of detection.That is 90 days in a standard test test does not detect the amount but presence of thc.The testing method measures drug molecule embedded in the hair shaft and not hair follicle.

That depends: Different tests may have different cutoffs. Some labs have a cutoff at 50 PG/MG. See: https://www.samhsa.gov/sites/default/files/meeting/documents/july_2013_moore_compliant.pdf 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