Hair Analysis

Test Overview

Hair analysis is done by evaluating hair structure and DNA from cells attached to the root of the hair. It can be used to find out if people are related. Forensic hair analysis can be done to help identify a person who may have been present at a crime scene. Hair samples are tested with specific chemicals and looked at under a microscope. Hair analysis can also be used to check for poisoning caused by metals such as lead or mercury. But hair analysis alone usually is not used for this type of testing.

Hair is a protein that grows out of hair follicles in the skin. Normally, a hair grows in the hair follicle for many months, stops growing, and falls out. A new hair then grows in the follicle. Hair samples do not show recent changes in the body, such as drug use within the past few days. But a hair analysis may show drug use or exposure to chemicals that occurred over the last few months.

Why It Is Done

Hair analysis is done by evaluating hair structure and DNA from cells attached to the root of the hair. It can be used to find out if people are related. Forensic hair analysis can be done to help identify a person who may have been present at a crime scene.

Hair samples that are taken close to the root can show what drugs were used up to 3 months before the test.

How To Prepare

If you have a hair analysis done, the lab will give you specific instructions on how to prepare your hair. Hair preparation and the part of your body from which the hair is taken vary.

How It Is Done

Hair analysis is done by collecting a hair sample and sending it to a laboratory.

Hair samples are taken from a specific part of the body, such as from the back of the scalp by the neck or from the pubic area. Hair samples are generally collected from the section of the hair closest to the skin. Hair close to the skin or scalp includes the most recent growth, which provides the most accurate information about what has occurred recently in the body.

Hair samples are washed in special chemicals before testing.

DNA profiles

Hair samples for DNA analysis will be gathered by laboratory personnel or law enforcement officials or a forensic examiner. For DNA testing, the hair must include the root. This requires that the hair be plucked, not cut.

Drug testing

Hair samples that are taken close to the root can show what drugs were used up to 3 months before the test.

Risks

There are no known risks from having this test.

Results

Hair analysis can be a useful tool, but there’s still a lot to learn about it. Because of this, you could be asked to take a different type of test so the results can be compared.

Results of drug testing will include the name of the drug and if the test is positive or negative. Negative results mean no drug was found.

Positive results are usually followed up with different tests to confirm the results of the first test.