Laser hair removal may be the most popular procedure at your clinic – but do most of your technicians actually understand how the hair cycle works? If they don’t then the following article is required reading for each of your treatment specialists.
Hair has two distinct structures – the follicle and the shaft. The follicle is located beneath the scalp in the skin and the shaft is visible above the scalp. The hair follicle contains several layers including the papilla, containing tiny capillaries to nourish the cells, and the bulb, where hair cells are growing and dividing. An inner and outer sheath surround the follicle and protect the growing hair shaft up to the sebaceous gland. The hair shaft is made out of a hard protein called keratin that is made up of three distinct layers. Hair on the scalp grows approximately .3 to .4mm per day or about 6 inches per year. At any given time hairs will be in one of three growth stages: anagen, catagen and telogen.
The anagen cycle is the active growth phase of hair. Hair in the stage will grow approximately 1cm every 28 days and stays active for two to six years. This can vary by person which is why some people have difficulty growing their hair longer.
The catagen phase is transitional and an estimated 3% of hairs are in this phase at any time. Lasting two to three weeks, hair growth stops and begins to detach and shrink from the sheath forming what is known as a club hair.
The telogen or “resting” phase accounts for 6% to 8% of all hairs. This phase lasts up to 100 days. Pulling on these hairs reveals a solid and white material at the root. On average it is normal for patients to shed anywhere between 25 to 100 hairs daily while in the telogen phase.
Familiarizing oneself with the life cycle of the hair follicle is important to understanding how laser hair removal works. It is only during the anagen growth stage that hair follicles are able to be targeted by lasers because of the abundance of melanin. At any given time at least 15% to 20% of hair is in the anagen phase. This is why laser hair removal is most effective after at least 6 to 8 treatments. The Candela GentleLASE is one of the most effective lasers offered on the market at targeting hair during this period.