How Philips’ Intense Pulsed Light technology works

Hair growth

Hair growth rates differ from person to person, depending on age, 

metabolism and other factors. However, everyone’s hair normally grows in 

3 phases. 

1  Growing phase (anagen phase)

The hair grows actively from the root. In this phase the concentration of 

melanin is highest. Melanin is responsible for the pigmentation of the hair. 

Melanin concentration is also the determining factor for the efficacy of 

the Intense Pulsed Light technology. Only hairs in the growing phase are 

susceptible to treatment with light.

2  Degradation phase (catagen phase) 

Hair growth stops and the root shrinks before the hair sheds. 

3   Resting phase (telogen phase) 

The old hair separates from its hair follicle and sheds. The follicle remains 

at rest until the biological clock tells it to become active again and grow a 

new hair.

Working principle 

 - The appliance works by heating up the hair and root beneath the skin. 

The melanin in the hair and hair root absorbs the released light pulses. 

The darker the colour of the hair, the more light can be absorbed. This 

process stimulates the hair to go into the resting phase.

 - In between treatments, hair sheds naturally and regrowth is inhibited. 

Hairs can take one or two weeks to shed.

 -  Optimal hair removal cannot be obtained with a single session, since 

only hairs in the growing phase are susceptible to treatment with light. 

During a treatment, hairs on the treated area are usually in different 

stages of the hair growth cycle. To effectively treat all hairs you have to 

repeat the treatment once every two weeks for the first two months. 

An integrated optical filter ensures that no UV light reaches the skin 

and ensures that the appliance is safe for the skin. 

ENGLISH

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