The Science of Laser Hair Removal

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Many of our clients at Be.aesthetics, are interested in the theory behind Laser Hair Removal. ‘Gold standard’ Diode Laser hair removal is based on the theory of selective photo thermolysis. This theory was developed from the clinical work showing that the hair follicle can selectively absorb energy sufficiently to disable it without causing damage to the surrounding tissue unlike IPL.

In order to achieve this the high powered Eneka diode laser with a wavelength that is highly absorbed by the melanin (dark pigment) that surrounds the hair follicle is required. At the same time the skin must be protected or cooled to prevent it overheating and causing damage, which is what the Eneka PRO has.

To achieve destruction of the hair follicle at the base of bulb of the follicle and the bulge which contains germ cells must be heated up to 70 degrees in order to prevent regrowth of the hair. To do so will achieve permanent destruction of that particular hair follicle and it will not grow back. The challenge for laser techs though is that the skin begins to damage at 44 degrees so how do we heat the follicle to over 70 degrees while keeping the skin well below 44 degrees?

One essential element in achieving this objective is efficient skin contact cooling! Keeping the surface of the skin cool while the laser energy is delivered deep in the follicle. This also maximises client comfort, not only does our machine have a super cool cooling system, but we can also apply additional cooling to the area being treated. Other factors such as skin type or colour, hair colour and hair thickness all effect the level of absorption and the energy required to achieve follicle destruction. Darker skin has a higher melanin content, and this slightly reduces the energy reaching the follicle. Finer lighter hair has less melanin and therefore less target for the energy so higher energy is required.

Another important element is the time it takes for the skin and the hair to lose heat immediately after each laser pulse, this is called the Thermal Relaxation Time. Skin cools much quicker than the follicle so delivering the laser energy in a fraction of a second to allow the skin to dissipate heat but keeping the follicle heat allows maximum heating of the follicle whilst protecting the skin. This time is called Pulse Duration. A very short pulse duration is recommended for best results on finer lighter hair.


What is the best technology?

A laser that combines high power, contact skin cooling, high absorption wavelength and shot pulse duration can safely heat the follicle for destruction of the hair and permanent removal. Not all lasers can successfully achieve this. There are many low powered lasers available without skin contact cooling that will simply damage the hair follicle not destroy it. Without effective skin contact cooling the energy will have to be lowered to avoid skin damage and as a result the required energy only makes it a short way down the follicle. The hair may appear to be removed but it has not been destroyed (Just stunned) and will eventually regrow.

As a result, you will require continuous ongoing treatment, with results no better than waxing. Many home bought IPLs operate like this as they do not have a single wavelength or the required energy needed resulting in lots of wasted energy or effective targeted skin cooling. Many cheap laser systems, often from places like China, have flooded the market but they simply do not have the power or cooling to achieve long term effective permanent results.

To achieve a short pulse duration requires high power. Their low price is attractive to clinic owners but the poor quality of treatment costs them in the long run. Investing in a high quality laser that can deliver high power, effective cooling and short pulse duration can achieve permanent results in a little as 6-10 sessions saving clients lots of time and certainly money as well as being a safe and comfortable treatment.

The Eneka PRO Diode Laser Platform offers these characteristics. Eneka PRO with up to 5000 Watts of energy and two modes pain free FHDR and DHR mode is twice as powerful as any other Diode laser and has USP (Unique Short Pulse) technology and sophisticated Saphire integrated skin contact cooling system.