Hair Strand Drug Testing?

Has anybody had to have a hair strand drug test? If so what should I expect? Are there any blockers or shampoos that REALLY work? If you have a prescription for something can they tell if you are using more than prescribed?

Hair Strand Drug Testing?

I have had to have hair strand drug tests, as well as many, many urine tests. With the hair strand test they will pluck a hair at random, usually from the top of your head, to test. They will also pluck a second hair as a backup. If your head is shaved or you have extremely short hair sometimes they will pluck a body hair, but since they generally only test the first 3-5 cm (1-2 inches) of hair that's not often. When sent to the labs the hair will be cut into segments and tested for metabolites that leave a "ring" on the hair. Some labs do not cut the hair into segments, but doing so allows them to date your use to approximately the week you did it within the last 90 days. There is some error depending on how fast your hair grows. Some shampoos really DO work, as they target and dissolve certain functional groups of the metabolites. Although I can't claim first hand experience with them I do know that the site http://drugtestforall.com/hair-drug-test... only sells quality products that work. I've used their urine products twice and passed both times. So far as prescriptions go most drug tests only test for the PRESENCE of metabolites, not the drug or concentration of the drug itself. If you're using aderall you will test positive for amphetamines, but they won't know if you're using one pill twice daily or ten pills every 6 hours. It's the metabolites they're looking for, and only a yes/no designation. Hope this helps, and good luck.