In short.. No
As the hair grows, it absorbs special markers called fatty acid
ethyl esters (FAEEs) and ethyl glucuronide (EtG) into its structure,
which remain in the hair indefinitely. No amount of washing or lice shampoo will remove these markers. If you have drugs in your system they will be detected. Especially cannabis, which can stay as a marker on the hair for anything up to 3 years.
