• Núria Estapé, science journalist

    Intense pulsed light (IPL) for permanent hair removal

    Intense pulsed light (IPL) is becoming popular among aestheticians and dermatologists as the method of choice for permanently removing facial and body hair. As a hair removal method, it is safe, effective and comfortable. It also has applications for treating abnormal hair growth, vascular skin damage and sunspots. Can IPL affect the skin’s health?


    In the coming years we may well see a rise in the use of IPL, an improved laser system. The laser emits broad-spectrum wavelength radiation (between 550 and 1200 nanometers) that reaches the skin at different rates. Very rapid light pulses (around 2,600 rays per second) project the particles (photons) onto the skin. The hair root (follicle) becomes so hot that the melanin content is damaged. After a few sessions the hair growth cycle is permanently altered.

    Laser depilation, although very similar to IPL in its mechanism of action, uses more localized wavelength spectra, depending on the type of laser being used. This makes it less effective for some skin types, especially the lighter tones that are less sensitive to some wavelengths.


    More effective than depilation

    Electrolysis used to be the most commonly used depilation treatment until, in 1997, the US Food and Drug Administration (FDA) recognized IPL as a permanent hair removal method after numerous studies demonstrated its effectiveness.

    In one comparative study, 25 women with facial hirsutism (excessive hair growth in  typically male areas) were treated with electrolysis on one side of the face and IPL on the other side of the face. When satisfaction levels were assessed, the electrolysis-treated sides and IPL-treated sides were found to have scored 5.4 and 8.3, respectively.

    Another study of 34 people with excess facial hair showed that hair growth was reduced by 76% in 3.7 IPL treatments, with maximum efficiency between the first and third sessions. Most importantly, however, IPL treatment effectiveness does not depend on skin type of skin, hair colour or the area of application.


    Skin blemish removal

    IPL is not only effective for hair removal; in cosmetic medicine it is used to treat vascular skin lesions and pigmentation disorders (vitiligo, melasma or moles) and to remove sunspots, which appear with age and in response to sun exposure. IPL is also indicated as a rejuvenation technique, since it increases collagen synthesis at certain intensities of radiation and so helps skin regeneration.


    Not entirely risk-free

    The popularity of IPL for removing unwanted hair and healing damaged skin has led to home sales of IPL kits, potentially dangerous in inexpert hands. In people with sensitive skins, IPL can cause side effects such as redness, scab formation and pigmentation changes. There are even studies that show paradoxical hair growth, of unknown origin.