No, hair follicle testing does not test for Benzodiazepines.
Hair follicle tests normally won't test for Xanax(benzodiazepines) They usually will only test for Methamphetamines, THC, Cocaine, Opiates & Phencyclides(PCP) All drugs stay in your hair. 1 inch of hair is approx. 60 days of past use. Most will test 90-120 days back. If they test for Benzos and you have used within that time, it will show up.
I was under the impression that the hair follicle test, test the 5 panels; cocaine, THC, Meth, Opiates, and Hallucinagenics, I may be wrong, but all the web sites I've researched have said this same thing to me .Good Luck!!