It can take six to twelve weeks for a hair to grow from the papilla to the surface of the skin.
Every hair on our body has three phases of hair growth: Anagen (active stage), Catagen (short transitional phase between the Anagen and Telogen) and Telogen (resting phase preparing to reset into the Anagen stage). All three phases occur simultaneously. Each hair follicle is independent and goes through the growth cycle at different times, otherwise all your hair would fall out at once. At any given time about 85%-90% of your hair is in the Anagen phase, 1-2% is in the Catagen phase, and 10-14% is in the Telogen phase.
The main difference between body hair and head hair is in the duration of the Anagen phase. The Anagen phase for arms, legs, eyebrows, etc. lasts just 30-45 days as compared to head hair which lasts 3-7 years. The longer the hair stays in the Anagen phase, the longer it will grow.
At the end of the Anagen phase, your hair enters the Catagen phase. A short transitional phase that lasts approximately 10 days. The hair bulb is pushed upwards and becomes keratinized. It appears short and thick and is referred to as club hair. Growth stops and the outer root sheath shrinks and attaches to the root of the hair. This is the formation of what is known as a club hair.
The Telogen phase is the final phase known as the resting phase when your hair is released and falls out. Growth stops, and the entire structure rests for a variable period of time, ranging from one and one half months for upper lip hairs to three to six months for leg hairs. The remaining club hair is ejected, and the Anagen phase commences again.
The Anagen phase is the best phase to target as it is well situated in the follicle for the IPL to seek and destroy.
Due to the different cycles, 6-8 treatments are recommended on average, spaced out according to the growth cycle. The time it takes to complete a full program varies from person to person and the location of the hair on the body, but is typically 12-24 months.
Patterns of hair growth vary greatly depending on whether the patient is male or female. In addition, ethnicity and health issues can determine patterns of health growth. Treating in the correct phase of the growth cycle and knowing your client’s medical and ethnic history impacts the success of the laser hair removal treatments.
To learn more read; Busting laser hair removal myths by Dr. Gloria Octaviano