Principle and Technology behind Laser Hair Reduction
- Laser Hair Reduction targets just the hair follicle without causing any thermal damage to the surrounding tissues.
- The hair follicle is selectively destroyed over a period of few sittings.
- Laser light is absorbed by the melanin in the hair. The light is converted to heat. Heat damages the bulge and the bulb, thereby disabling the hair structure.
- Laser light is not absorbed by gray, blonde or red hair.Hair must be black or brown in order to target the hair follicles.
- Most lasers are equipped with a cooling device that reduces the discomfort from the laser light and also protects the top layer of skin from excessive heating and potential changes in pigmentation.
Hair Cycles and Role in Number of Treatments
Because hair grows in cycles, repeated treatments are necessary to destroy the hair follicles.
Hair cycles: Hair growth has three cycles and the length of hair growth varies depending on different parts of the body.
- Anagen is the active phase of hair growth when the laser reduction is effective. Hair during this stage has an abundance of melanin and the cells are dividing rapidly.
- Catagen is the transitional phase, which lasts for 2-3 weeks. 3% of hair are in this phase.
- Telogen is the resting phase of the hair follicle when the hair falls out in preparation for the development of new hair.
- Number of Treatments:About 5-8 treatments are needed at 4-6 weekly intervals for best results. It is pointless to schedule closer visits because the laser targets the hair in the active growth phase or the anagen phase.
- The percentage of hairs removed per session varies by location on the body, with thinner-skinned areas such as underarms and bikini area generally responding better than thick-skinned areas such as the back.
- About 10 percent to 25 percent reduction in hair growth can be expected with each treatment.
- Treatments are repeated every four to eight weeks.
- The hair that regrows following treatment tends to be lighter and finer in texture.
- Avoid sun exposure and use a broad-spectrum sunscreen with a Sun Protection Factor (SPF) of 30 or higher following theprocedure.
Types of Lasers
The ruby, alexandrite, diode and intense pulsed light systems were the first lasers approved by the U.S. Food and Drug Administration (FDA) for hair reduction.
Lasers work best on light-skinned, dark-haired individuals because the light from these lasers is not significantly absorbed by dark pigments in the surrounding skin.
Devices with longer wavelengths, such as Nd:YAG lasers, have the ability to treat darker skin types. Nd:YAG lasers and diode lasers are the safest for Asian skins.
What Patients Should Know
- These procedures may be offered in informal settings such as shopping malls, spas and walk-in clinics, but it's important for patients to choose an experienced dermatologist.
- Treatments should be performed by or under the direct supervision of a dermatologist or other physician who has appropriate training and expertise.
- In general, five or more treatments are required to achieve permanent hair growth reduction.
- Darker, coarser hair respond best to laser hair removal. Lighter,and fine hair is least responsive
- Patients seeking laser hair removal are advised to avoid tanning.
- The most common side effects include discomfort, swelling, and redness that last one to three days, which should not happen in trained hands.
- Other possible side effects include blistering, herpes simplex outbreaks, bacterial infections and temporary skin lightening or darkening.