People have practiced the same basic – and painful - Hair Removal Techniques throughout most of history. Laser hair removal represents a major scientific leap forward.
Hair is removed with a beam of light produced by a LASER and projected through a fiber optic cable to the selected area on the skin.
The laser produces light in a single wavelength adapted to the color of the desired target. For hair removal, the target is the hair and its follicle; both contain a dark pigment called melanin.
An Alexandrite laser emits a 755nm wavelength specific for melanin. When laser light falls on a hair/follicle, the melanin absorbs the light energy and converts it into heat, burning the hair away.
The beam is just strong enough to destroy hair but too weak to damage the skin. This process is called Selective Photothermolysis.
This process is called “selective” because it targets only the hair through its melanin pigment and not the skin (fair skin only). The word ”photo” means light and “thermolysis” means destruction with heat. The surrounding skin is usually cooled by an active external cooling device (cold pulsed air, cryogenic gas or spray) or by a passive cooling mechanism (a cold piece of glass underneath the hand piece), generally considered as less efficient than cold pulsed air or cryogenic gas.
It is important to note that that all skin also contains the Melanin pigment to various degrees.
The ideal laser hair removal candidate has dark hair against fair skin.
Those who have dark skin either by ethnic origin or by sun tanning are usually not good candidates for Alexandrite laser treatment.Fortunately, with recent advances in laser technology, new lasers are now available for pigmented skins, such as the NdYAG 1064nm Long Pulse.
Your laser physician will determine during your initial FREE consultation both your skin type and the type of laser to be used on your skin.A test will then be performed on a small area, approximately 1 inch square.
Laser Hair Removal should not be confused with electric hair removal, which is also called electrolysis. This painstakingly long process destroys hairs one by one, with an electric pulse going through a needle planted in a hair shaft (in the skin) down to the follicle. Laser is less painful and much faster has replaced this old technique. Nevertheless, electrolysis may occasionally be used as a complement to laser when a couple of hairs are left on a small area.
Permanent hair removal can only occur during a hair’s growth – or anangen phase.
The hair cycle has 3 phases, but the hair cycle is different from one area of the body to another.
For example, on the chin, the hair cycle lasts 16 months, the number of hairs in the anagen phase is 20% and the anagen phase duration is 9 weeks.
On the bikini line the hair cycle lasts 18 months, the ratio of hair in that phase is 30% and the anagen phase duration is 22 weeks.
On an upper lip, the cycle lasts 9 months, the anagen phase lasts 12 weeks and the ratio of hair in that phase is 40%. Fortunately, during the anagen phase, a hair is full of melanin, making it a perfect target.
Since all hairs are not in that phase at the same time, several sessions are necessary to treat a specific area.
On average, 5 to 7 sessions are enough to treat most zones except the chin, the thighs and the upper back, which may require up to 9 sessions.
What type of parameters will your laser physician use to design your personalized treatment or protocol?
- Pulse duration: long pulse lasers are considered the safest (Alexandrite or NdYAG). Value in milliseconds (msec).
- Fluence: power or quantity of energy delivered to the skin, adapted to skin type and hair quality. Value in Joules/cm2 (J/cm2).
- Delay or Repeat Rate: length of time between two pulses. Has an impact on both skin and hair thermal relaxation times. Value in Hertz (Hz).
- Spot Size: diameter has a direct impact on both speed and depth of light penetration.
A good spot size selection directly affects the quality of your results. It will allow an adequate target to capture the hair and its follicle exactly where they are.Value in Cm.
- Skin Cooling (time, volume, fan speed, cold ratio): it allows the skin to be properly cooled when the laser beam hits the skin. A spray of cryogenic gas or constant pulsed refrigerated air is the best system available today.
Information presented in this section is based on data drawn from various publications, scientific articles and reports published in the US and in Europe.