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Hair Drug Test

Hair test is an analysis of chemicals, i.e. harmful substance, drug residues, metabolites, etc, in hair samples, which provides information of the type, identity and concentration of target molecules. Hair-drug test is a unique drug testing technology patented by Wah Kin. It detects the most commonly abused drugs in Hong Kong with higher accuracy and sensitivity.

For more information, please visit Hair-drug Test .



Drugs or drug metabolite circulates are deposited in the hair follicle and entrapped in the core of the hair shaft. Since scalp hair grows on an average of 1.3 cm per month, therefore different segments of a hair strand corresponds to different detection windows revealing the drug intake history:


 Hair length

 Corresponding drug history

 Hair root - 4 cm

 Past 3 months

 4 - 8 cm

 Past 4 – 6 months

 8 - 12 cm

 Past 7 – 9 months

 12 - 16 cm

 Past 9 – 12 months









Drug targets covered by hair-drug test: 

1. Cannabis

2. Cocaine

3. Norcocaine

4. Benzoylecgonine

5. Cocaethylene

6. Heroin

7. Morphine

8. Methadone

9. Codeine

10. Amphetamine

11. Methamphetamine

12. Ecstasy including MDMA, MDEA and MDA

13. PCP

14. Ketamine