Will you test clean for a hair follicle test if you only used cocaine one time?

It generally depends on how long ago you used cocaine prior to the testing. Hair follicle tests are very simple and very accurate and that is why they are commonly used when testing for cocaine.

HOWEVER test have a threshold level that one must go over to be detected as a positive. one persons "one time" is A line or A hit or it may be A day of use. if it is small enough then it would'nt show up.