Understanding laser hair removal

Laser hair removal has become the ‘Gold Standard’ method for fast effective hair removal

Laser hair removal is based on the principle of selective photothermolysis in which light energy is delivered to the treated area in such a manner as to maximise tissue damage to the hair follicle while sparing the skin. Melanin is the pigment in both hair and skin that gives them their colour. There is much more melanin present in hair than in skin and this means that the hair absorbs more of the laser light energy than the skin. The laser is attracted to the pigment in the hair follicle where it is converted to heat energy. This heat energy can cause a lethal injury to the hair follicle stem which is important for regeneration of the hair follicle. Laser hair removal works best on the hairs that are in their ‘anagen’ or active growth phase when the stem cells are active.

The Best candidates

Laser hair removal works best on patients with the combination of light skin and dark hair because the laser energy is absorbed more by the pigment in the dark hair follicle than the pigment in the skin. Tanned skin ‘robs’ laser energy as it passes through the skin to the hair follicle.  Patients who are tanned should wait for the tan to fade for best results

The Sciton BBL machine is used for hair removal in non-tanned skin and is used at COSMOS for patients with skin types one to four.  Infrared lasers such as thee Sciton 1064nm YAG are less dependent on skin colour and are suitable for naturally darker skin types.

Because the pigment in the hair is the target for laser energy, gray or white hair (which lacks pigment) cannot be effectively treated with any laser.

Patients using Roaccutane should wait 6 months after ceasing the medication before laser lair removal treatment.

Herpes Simplex virus (cold sores) can be activated by the laser hair removal around the lip and patients that may be affected should commence with antiviral medication before the treatment.

The procedure

Hair should not be plucked or waxed for at least 3 weeks before laser hair removal. This removes the hair shaft from the hair follicle, thus removing most of the pigment (melanin) which is the target of the laser beam. Hair should be shaved before the treatment. This preserves the pigment in the hair follicle and prevents the uptake of energy by the external hair. This will allow for a more effective treatment with reduced levels of discomfort.

What Does The Treatment Involve?

All laser devices used for hair removal involve the application of laser energy over the treatment area, with some mechanism to cool the skin. The amount of discomfort depends on the amount of absorption, either by the pigment (melanin) in the skin and the hair follicle. Discomfort increases with increased laser energy, increased hair size and density, and darker skin types. The discomfort feels similar to the flicking of an elastic rubber band on the skin. The discomfort is reduced by cooling the skin and anaesthesia prior and post the delivery of the laser energy.

What Do I Do After The Treatment?

In most cases, little needs to be done. Mild burning sensations and redness can be treated with ice packs and oral paracetamol. In cases where blisters occur it is recommended that patients call the clinic for further advice. Sun exposure should be avoided and a sun block should be worn at all times.

During the weeks after the treatment, the damaged hair follicles are extruded or shed, and may be misinterpreted as early regrowth of hair. This is especially noticeable in areas with thick, course hair

Expectations

Multiple sessions are needed for the best results. Laser hair removal works best on the hairs that are actively growing (anagen hair follicles). As the dormant hairs (telogen hairs) become active, usually within 3 weeks to 3 months, some new hair growth will be observed. Usually at least 6 to 8 treatments are necessary to achieve satisfactory, long lasting results. Treatment sessions are spaced out every 6-8 weeks. The female face, armpits and bikini lines are areas which respond fastest to laser treatments. Backs, arms, legs and chest usually need more treatments.

The permanence of laser hair removal is often questioned. In practice, no laser destroys all of the hair follicles. Some follicles are destroyed, others are miniaturised, and some are shocked into prolonged dormancy. It's possible that with a sufficient number of treatments, true ‘permanent hair removal’ can be achieved however this may not occur for every single hair in the treatment area. As an example, only 30% of hair follicles on the back are in anagen (active growth) at a given time and 70% of the hair follicles are in the resting phase of growth. Assuming a single laser treatment permanently eliminates every actively growing follicle (the actual figure may be close to half), 70% of the hair follicles will remain. After another 3 months 30% of these hair follicles will enter the active growth stage, and if a second laser treatment eliminates every actively growing follicle, then only an additional 21% of the original hair follicles will be destroyed, leaving 49% of the original hair follicles able to regrow visible hair. A third treatment will leave 34% of the original hair follicles, a fourth 24%, and so on. So, there is an exponential decreasing reduction with multiple treatments which is a permanent.

What Is The Difference Between The Various Lasers/Light Sources Available?

IPL or Intense Pulsed Light is the most common machine used for hair removal. Technically it is not a laser as it emits a broad-band of light frequencies rather than a single wavelength. IPL systems are effective for hair removal.

At Cosmos cosmetic medicine, we utilise the Sciton BBL or the Sciton 1064 nm (Nd:YAG). These wavelengths are not attracted so much to the melanin in skin and are the safest and most effective laser for people with darker skin types, including Asian, European, Indian, African, and other darker skin types. Furthermore, these Lasers have contact cooling which allows the skin to be cooled during treatment and this reduces the likelihood of skin damage.

What Are The Side Effects and Complications of Laser Hair Removal?

Redness and swelling are relatively common. Blisters may occur, especially in dark or tanned skin patients, and these patients may experience transient pigmentary changes such as lightening or darkening of the skin, which may last weeks or occasionally months. The risk of scarring or infection is very low, but may occur if there is blistering which is contaminated or irritated. Cold sore outbreaks may occur when the perioral area is treated and herpes can be reactivated when the bikini areas are treated.

For more information please call 1300 138 797 or email info@cosmosclinic.com.au