Drug tests and in particular testing hair for drugs is becoming far more commonplace, especially across western Europe and North America. This approach to drug testing has one major advantage over other detection methods such as saliva, urine and blood, in that it provides a far wider timeframe for which drugs can be detected. (This is commonly known as the detection window). It is possible to detect drugs for several months - even years if the hair has been allowed to grow for that long. Most commonly however, tests require 90 day detection: This compares to just 4-5 days for fluid based testing (or in severe cases of marijuana misuse, 28 days)

Approximately fifty strands of hair are needed for successful hair testing. This is about the thickness of the end of a shoelace, meaning that most people would show no obvious signs that any hair had been removed unless their hair is particularly short.

The cost of hair testing is higher than urine based tests - which are the only other viable method of achieving top-quality test results. Testing using blood is not widely available mostly because of the challenges in taking a sample in the first instance.

A typical hair drugs test costs around £60-£70 for preparation of the sample (which involves turning the hair from a solid to a liquid) and then an additional £40-50 per drug type required for detection. This compares to an approximate cost of £60-75 for laboratory testing of urine which will detect substances of misuse across all drug classes.

One of the most common questions how to pass a hair drug test. Very simply, there is only one sure-fire way in which to guarantee this - Don’t take drugs!

Sweet News