Hair drug testing is effective for long term detection of drug use, up to 90 day. It is for this reason that many judges are ordering hair drug testing. Hair testing for EtG alcohol will show a 90 day lookback for consumption of alcohol so this is very effective in alcohol monitoring programs. Many individual that suspect they have been a victim of a date rape drug will find the hair drug test to be more effective then urine drug testing.
What if the person is bald? Can body hair be tested for drugs or alcohol?
If the head hair is not long enough or shaved, then a sample of body hair from the legs, chest, or armpits, and occasionally beards can be used instead. Body hair typically grows at a less predictable rate than head hair which is about ½ of an inch per month. Using body hair for a hair follicle test may provide a look back of up to 6 months. A positive hair drug test result does not actually indicate the exact date or dates the drug was used, just that it was ingested in an estimated timeframe within the last 90 days