Page 102 - Blog Posts v1

A31 - A brief description of laser/IPL hair removal - in 13 comments.
This post describes the 13 main features behind laser/IPL hair removal:
1. Light, usually red, is fired at dark hair (red light can penetrate far into the dermis);
2. The aim is to heat up the melanin in the hair shaft so that the germ cells can be ‘cooked’;
3. This only happens in the actively growing anagen phase;
4. Some of the light energy is absorbed by epidermal melanin (darker skins absorb more than lighter skins, and so, become ‘hotter’);
5. This generates temperature above 45C which triggers the thermal pain receptors, just below the dermal-epidermal junction;
6. Pre-cooling the skin lowers the temperature of the pain receptors, thereby reducing pain;
7. If sufficient heat is generated in the germ cells, over a sufficient length of time, they will cook irreversibly;
8. Post-cooling the area after the treatment will remove any excess heat energy;
9. Less than 10% of the heat energy is used to kill the germ cells;
10. The follicles cannot regenerate if all the germ cells are cooked;
11. Only around 50 to 60% of the anagen follicles will be killed in any one session;
12. The longer the gap between repeat sessions, the more anagen follicles will be presented for the next treatment - this means fewer sessions overall!
13. The thickness and density of the hairs are not important, as long as sufficient fluence is applied.
In a nutshell, light is converted into heat which ‘cooks’ the target germ cells - but only if the correct does of light energy is applied over the correct length of time.
Mike’s Blog Posts 102