Hair Growth and Light – The Technology
How can light be used to remove hair? The technology behind the product
IPL[Intense Pulsed Light] devices remove hair with light-based technology. The removal of hair by light waves is based on the theory of selective photothermolysis, which uses optical energy in order to prevent further hair growth and remove existing hair.
This effect is reached by the fact that the skin pigment melanin absorbs the energy of the light and is changed through this absorption of heat. The hair follicles are then deactivated and the growth of hair is impeded. The more melanin one has in the their hair (i.e. the darker one’s hair is), the more light can be absorbed, and the more effective the removal of hair will be. For especially light-colored or blonde hair, light-based hair removal is difficult, as there are relatively lower levels of melanin available.
IPL – Intense Pulsed Light
Beurer’s IPL devices use an impulse of Xenon light, which creates light with a wavelength between 475 and 1200 nm and crosses several light spectrums (broad-spectrum) – from visible to infrared. This method is especially well suited for deactivating hair follicles, resulting in long term removal – especially of darker hair. During use of the devices, energy of about 5 J / cm2 is given off. With the help of controlled impulses the light penetrates the skin only deeply enough to affect the hair follicles, and not hurt the skin.
The Hair Growth Cycle
Each and every hair on the body goes through three different phases of the hair growth cycle, namely: the Anagen phase (growth phase), the Catagen phase (maintenance stage), and the Telogen phase (pause/falling out stage). The length of the entire hair growth cycle is different from person to person and also depends on the body part that the hair is located on. Typically, however, the cycle lasts between 18 – 24 months.
Only hair which is currently in the Anagen – growth phase, will react to light-based hair removal treatment. Therefore it is important to note, that several treatments are often necessary, in order to remove all hair. Sometimes this can require the length of an entire hair growth cycle in order to remove an entire body’s worth of hair.