Laser hair removal is a medical procedure whereby body hair is treated with a laser light to discourage re-growth. With a few repeated sessions, it may can eliminate the need to shave beards, legs, underarms, bikini lines, backs, or other areas.
Melanin, a form of pigment, surrounds the hair follicles and absorbs heat from the treatment laser. The darker the hair color, the more melanin the hair contains and the more heat it absorbs. When it absorbs enough heat, it damages the re-growth mechanism and may kill the hair follicle. The hair falls out, and new hair may grow more slowly or stop growing completely.
Laser hair removal is not recommended for everyone, however. The skin also contains melanin, and the darker the skin, the more melanin it contains. If hair is lighter than the surrounding skin, the skin will absorb more heat than the hair. Therefore, a very tan person with blonde hair probably won't have much success with this treatment, while a fair person with dark hair is the ideal patient.
For people with semi-dark skin but darker hair, there are factors that work in favor of laser treatments. As long as the hair is darker than the skin, it will absorb more heat, and since the skin has a larger surface area, it cools faster than hair. Therefore, when pulses of laser light are used, and the skin is possibly treated with a cooling agent, the hair follicles can be kept hot, while the skin can be kept relatively cool.
In virtually all cases, multiple treatments are required, because hair can only be effectively treated when it is in a stage of growth termed the anagen phase. Since hair grows in cycles and does not enter the anagen phase at once, the sessions are spread out to treat new hair growth that was "dormant" in previous sessions. The number of sessions required varies between people.
Prior to laser hair removal, electrolysis was the favored method. Both require multiple sessions, but that's where similarities end. In laser treatments, the light shines over an area of skin that includes several hairs, treating multiple follicles at once. Electrolysis directs an electric shock to each individual hair, one at a time, and it is commonly reported to be uncomfortable. Lasers, on the other hand, might cause the skin to feel as if it's lightly sunburned, but is fairly pain-free.
The cost for this hair removal treatment varies, but experts stress the importance of finding a reputable clinic with experienced medical professionals. While patients commonly require three to five sessions for a good result, an upper lip is likely to require fewer treatments than the legs, back or chest.