How Long Does A Hair Follicle Test Go Back?

Posted on Tue, 1 Nov 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Tue, 1 Nov 2016 Answered on

Tue, 22 Nov 2016 Last reviewed on

Question : Hello

I just had a hair test today..I noticed when they collected my hair it was put in an envelope with foil with a ruler...I noticed the ruler went up to 10cm is the whole 10cm tested or just 1.5 inches the lady told me the test went back approx 90 days.....

Answered by Dr. Indu Kumar (3 hours later)

Brief Answer:
Whole hair is tested under the microscope.

Detailed Answer:
Hello,
Thanks for writing to HCM,
I've gone through your query and understand your concern,

Whole hair is tested under the microscope.Hair is observed under the microscope.
It can detect toxic deposition more than three months.

Pattern and nature of deposition is seen for diagnosis.

Get well soon.

Hope I have answered your query.
Further queries are most welcome.

Take Care
Dr. Indu XXXXXXX

Above answer was peer-reviewed by : Dr. Nagamani Ng