Updated: Jun 24, 2021
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.
It takes weeks for a hair sample to show changes in the body, because hair grows slowly.
Hair samples do not show recent changes in the body, within the past few days. But a hair analysis may show drug use or exposure to chemicals that occurred over the last few months.
For DNA testing, the root of one hair is needed to analyse DNA and to establish a person's genetic makeup.
Hair samples should be taken from the back of the scalp by the neck closest to the skin as this includes the most recent growth.
The hair should be plucked not cut as this provides the most accurate information about what has occurred recently in the body.
· Clip a small sample of your hair about 10 cm long
· Put the clippings in a plastic bag and seal it.
· Send the samples to Paragon Health Centre along with information about the type of hair treatments you have used, including shampoos, conditioners, colourings, bleaches, and permanents.
What the hair sample contains is determined not only by nutrition and internal metabolism but also by external substances.
Air pollution, mineral content of the water supply, exposure to industrial waste, shampoos, hair dyes, hair sprays, permanents, and bleaches may raise or lower the levels of certain minerals in the hair. Also, the use of medicines such as birth control pills can change the mineral concentration of hair.
Note: For more detailed information see the full article at MICHIGAN MEDICINE
Hair growth occurs in cycles consisting of three phases:
Anagen (growth phase): Most hair is growing at any given time. Each hair spends several years in this phase.
Catagen (transitional phase): Over a few weeks, hair growth slows and the hair follicle shrinks.
Telogen (resting phase): Over months, hair growth stops and the old hair detaches from the hair follicle. A new hair begins the growth phase, pushing the old hair out.
Hair grows at different rates in different people; the average rate is around one-half inch per month. Hair colour is created by pigment cells producing melanin in the hair follicle. With aging, pigment cells die, and hair turns gray.