How long does it take for a negative hair follicle test to come back?
Hair testing
Negative results, therefore, are generally available within 2-3 days, while positive test results may take up to a week to confirm. Though it may take slightly longer than urine tests, hair tests have the advantage of being able to detect drug use from many months before the specimen was collected.
What is the cutoff level for a hair drug test?
Screening cut-off levels followed the laboratory's standard practices for the 5-panel test: 1 pg/mg for marijuana, 500 pg/mg for cocaine and amphetamines, and 300 pg/mg for opioids; GC/MS confirmation cut-offs were: 0.30 pg/mg for carboxy-tetrahydrocannabinol (THC) metabolite, 500 pg/mg for cocaine and 50 pg/mg for ...
How many panels does a hair follicle test take?
A 1.5 inch sample of about 200 strands of hair (about the size of a #2 pencil) closest to the scalp will give 100mg of hair, the ideal sample for screening and confirmation. For EtG, add-ons and/or tests above 10-panel, 150mg of specimen is recommended. We recommend weighing the specimen on a jeweler's scale.