What is Laser hair reduction?

Laser hair reduction is the process of removing unwanted body hair which works on the basis of selective photothermolysis which target pigmented hair follicles using melanin as a chromophore. So these destroyed hair follicles shed off after few days of treatment.

How many no. of sessions are required for permanent reduction?
Hair are actually present in three phases (ie anagen, telogen,catagen) and laser would destroy only active growing follicles or which are in their anagen phase so it requires several sessions to kill hair in all phases of growth.
Most patients need minimum 6-7 sittings regular and after that maintenance sessions are required.
The number of sessions also depends on other parameters such as skin color, coarseness of hair, reason for hirustism.

Are there any side effects?

After laser , a little redness or mild swelling is normal around the treatment area. It subsides itself in half an hour. For more sensitive areas numbing creams can be used to avoid any discomfort.