A variety of laser and IPL technologies have answered our call for permanent hair reduction. They offer safe and effective treatment for long-term hair removal, which can be broadly categorised as laser, intense pulsed light and photodynamic therapies.
Light-based hair removal aims to remove unwanted hair using intense beams of light energy at varied wavelengths. This targets different structures of the skin and hair follicle pigments to destroy each hair individually, without damaging the surrounding area.
Permanent hair reduction offers a multitude of benefits compared with other hair removal options. Hair grows back less quickly and less thickly than shaving, waxing or creams, and typically there are no spots, ingrown hairs or itchiness when the hair does eventually grow back.
First we need to get our heads around our hair. Hair grows in a three-phase cycle – anagen is the active growth phase; catagen is the transitional period; and the resting phase is termed telogen. There is variation in the duration of anagen and telogen phases in different body sites. There is also seasonal variation, which means in summer there’s a higher rate of growth and slower growth during winter.
The growth phase is the only phase suitable for laser hair removal and, with only 85 percent of hairs in this phase at one time, a series of treatments is required for effective hair reduction.
Laser light is different to normal light for many reasons: it travels in a synchronised fashion; retains its intensity over a long distance; it is monochromatic (of the same wavelength or colour); and it can be pulsed.
The principle behind lasers is light absorption by targets that selectively absorb pulses of radiation. Selective absorption means hair follicles are destroyed but the skin is left undamaged. The same as a black car will be hotter than a white car because it absorbs more wavelengths of light, certain target tissues will absorb certain wavelengths of light more effectively. In the case of hair removal, the target is the pigment, or melanin, in the hair follicle that colours the hair.
Effectiveness is limited if there is no pigment – for example light blonde, white or grey hair. Second, in the telogen growth phase, the hair bulbs are un-pigmented and therefore do not absorb light. The early anagen phase is the best stage to maximise responsiveness to laser and light treatment.
Two or three days before treatment you need to either shave or use hair removal cream over the area to be treated. No sun, solarium or fake tan should be used two weeks before your treatment or superficial burning or pigmentation may occur.
Laser hair removal has been described as being similar to a small rubber band being flicked against your skin and any discomfort is typically soothed by a cooling device used simultaneously to take the hair out of the skin.
Efficacy depends on the area being treated and can be influenced by sex, age and hormones. However, studies show an average hair loss of approximately 80 percent after six to eight treatments, conducted six to eight weeks apart.
The Ruby laser (694nm), Alexandrite laser (755nm), Diode laser (810nm), Nd:YAG laser (1064nm) as well as IPL have been commonly used for hair removal. The Ruby and Alexandrite lasers are recommended for hair removal in patients with Fitzpatrick fairer skin types of 1 to 3. The Diode laser can be used in the range of Fitzpatrick skin types (1 to 5) – from fair with red hair to very dark skin. The long-pulsed Nd:YAG laser, functioning at a wavelength of 1064nm, can be used on all skin types and is the safest device for hair removal in very dark-skinned patients due to its long wavelength and the reduced risks of hypo-pigmentation.
Intense pulsed light
Intense pulsed light (IPL) uses light wavelengths that safely target either melanin or haemoglobin in the skin. While it was developed for skin concerns, a side effect of the treatment recognised and harnessed is the reduction of hair growth.
Intense pulsed (non-laser) light sources have been used primarily for hair removal in patients with Fitzpatrick skin type 1 to 4, and light hairs (blonde, grey and white) tend only to be treatable if they are coarse in nature. Unlike lasers, IPL devices produce a broad spectrum of light in a range of wavelengths. This versatility allows the characteristics of the light energy to be adjusted according to each patient’s skin type, specific condition and location of the condition.
During the procedure, pulses of intense light are fired at the skin through varying filters, which isolate specific wavelengths of light. Similarly to laser, the pigment is targeted and preferentially absorbed, heated and selectively destroyed by certain light wavelengths without damaging surrounding tissues.
A minimum of four to six treatments are likely to be required to see results and ongoing treatment is recommended. Darker skin colour and lighter coloured hair will require more treatments, as there is less melanin in the hair roots and the machine cannot be operated at full capacity.
A disadvantage of IPL systems is that most devices use large rectangular spots, creating difficulty in the treatment of convex or concave hair-bearing areas. It has been suggested the efficacy of IPL is increased when combined with radiofrequency (RF) energy, producing results similar to that of laser. The device delivers intense pulse light first to heat the hair follicles and RF supplies thermal injury to the treated area.
The usual downtime with IPL modalities is minimal to none. Straight after IPL a slight burning sensation can occur for a few hours. Temporary discolouration can occur for around three to four days after the procedure and will flake off slowly. Short-term side effects include reddening of the skin (erythema), temporary bruising and oedema (swelling). Reactions such as scabbing and blistering are possible though rare. It’s important to protect skin from UV light with daily sunscreen application.
Photodynamic therapy relies on a chemical reaction activated by light energy to selectively destroy specific tissues. When skin is exposed to a light source of an appropriate wavelength, its photosensitiser molecules are activated to produce oxygen intermediates that destroy the targeted cells. There has been evidence of photodynamic therapy working wonders for hair removal regardless of the hair colour or cycle, however more research is needed as it’s the newest kid on the block.
Hair removal tips & tricks
• An average of five to seven treatments are required for hair removal of more than 50 percent.
• Possible side effects include ulceration, blistering, scarring, acne flares, folliculitis, pigmentation changes, paradoxical hair growth, recurrence and poor response.
• Strict usage of broad spectrum sunscreen and avoidance of sun exposure for six weeks before treatment is recommended.
• For those with Fitzpatrick skin type 3 or above, and those with a history of recent sun exposure, a bleaching cream is advised prior to treatments.
• Avoid plucking, waxing and electrolysis to keep an intact hair shaft, however shaving, bleaching and depilatory cream before treatment is good to go.