Alexandrite & Nd:YAG laser wavelengths have high absorption on melanin, when laser is absorbed, the energy thermally damages bulge & bulb cells, these cells are responsible for hair growth and removing them prevents future hair regrowth.

The hair is rich in melanin & has a life cycle of 3 stages:

• Anagen: this growing stage is the ideal target of laser hair removal, the hair is fully attached to the bulge & bulb cells which can be thermally damaged by burning the hair.
• Catagen & Telogen: hair in this stage stops growing and is not attached to the bulge & bulb cells, hence burning hair by laser doesn't remove bulge & bulb cells. These cells can be removed once the hair cycle returns to anagen stage, which explains the need for multiple sessions.

Efficacy of hair removal necessitates using a pulse duration shorter than the Thermal Relaxation Time (TRT) of hair, when achieved, the hair gains temperature faster than losing it till it reaches the burning point.

The TRT of the hair depends on its size, smaller hairs have low TRT which needs low pulse duration to reach the burning point.

Clarity II avails 1 msec ,the lowest pulse duration in hair removal supported by the high protection by the patent ICD cooling, which makes it effective in thick thin & resistant hair.