The enzyme-linked immunosorbent assay, or ELISA, is used for initial tests on hair follicles, while results are confirmed using gas chromatography/mass spectrometry, or GCMS, notes Expomed. Recommended follicle-cleansing remedies include lemon juice and baking soda, explains Made Man. However, Expomed insists that hair follicle cleansers are ineffective.
Hair follicle testing is used to check for a wide variety of drugs, notes Expomed. These include phencyclidine, opiates, marijuana, cocaine and methamphentamines. Once in the bloodstream, these drugs eventually diffuse into hair follicles, creating a record that can be detected using specialized tests.
Hair samples for testing are normally obtained from the head, notes Expomed. Head hair is typically preferred because it can be used to establish both the drug types and time frames of abuse. When head hair is unavailable, hair from other parts of the body is used. However, body hair can only be leveraged to identify the types of drugs used and is ineffective for establishing the time frames of abuse.
Lemon juice, sea salt baths, baking soda pastes and home-brewed shampoos made from a mix of rosemary and grapeseed oil can be used to clean hair follicles in a way that makes it impossible for tests to detect drug use, according to Made Man. However, Expomed argues that these and other remedies don't work as the drugs are incorporated into the structure of hair follicles, making it impossible to wash away the evidence.