Laser hair removal is a medical procedure that uses a concentrated beam of light (laser) to remove unwanted hair.

During laser hair removal, a laser emits a light that is absorbed by the pigment (melanin) in the hair. The light energy is converted to heat, which damages the tube-shaped sacs within the skin (hair follicles) that produce hairs. This damage inhibits or delays future hair growth.

Although laser hair removal effectively delays hair growth for long periods, it usually does not result in permanent hair removal. Multiple laser hair removal treatments are needed for initial hair removal, and maintenance treatments might be needed as well. Laser hair removal is most effective for people who have light skin and dark hair, but it can be successfully used on all skin types.

Why it is done

Laser hair removal is used to reduce unwanted hair. Common treatment locations include legs, armpits, upper lip, chin and the bikini line. However, it is possible to treat unwanted hair in nearly any area, except the eyelid or surrounding area. Skin with tattoos should not be treated either.

Hair color and skin type influence the success of laser hair removal. The basic principle is that the pigment of the hair, but not the pigment of the skin, should absorb the light. The laser should damage only the hair follicle while avoiding damage to the skin. Therefore, a contrast between hair and skin color — dark hair and light skin — results in the best outcomes.

The risk of damage to skin is greater when there is little contrast between hair and skin color, but advances in laser technology have made laser hair removal an option for people who have darker skin. Laser hair removal is less effective for hair colors that do not absorb light well: gray, red, blond and white. However, laser treatment options for light-colored hair continue to be developed

How you prepare

If you are interested in laser hair removal, choose a doctor who is board certified in a specialty such as dermatology or cosmetic surgery and has experience with laser hair removal on your skin type. If a physician assistant or licensed nurse will do the procedure, make sure a doctor supervises and is available on-site during the treatments. Be cautious about spas, salons or other facilities that allow nonmedical personnel to do laser hair removal.

Before laser hair removal, schedule a consultation with the doctor to determine if this is an appropriate treatment option for you. Your doctor will likely do the following:

• Review your medical history, including medication use, history of skin disorders or scarring, and past hair removal procedures
• Discuss risks, benefits and expectations, including what laser hair removal can and can not do for you
• Take photos to be used for before-and-after assessments and long-term reviews

At the consultation, discuss a treatment plan and related costs. Laser hair removal is usually an out-of-pocket expense.

The doctor will also offer specific instructions to prepare for laser hair removal. These might include:

• Staying out of the sun.Follow your doctor is advice for avoiding sun exposure before and after treatment. Whenever you go out, apply a broad-spectrum, SPF30 sunscreen.
• Lightening your skin.Avoid any sunless skin creams that darken your skin. Your doctor might also prescribe a skin bleaching cream if you have a recent tan or darker skin.
• Avoiding other hair removal methods.Plucking, waxing and electrolysis can disturb the hair follicle and should be avoided at least four weeks before treatment.
• Avoiding blood-thinning medications.Ask your doctor about what medications, such as aspirin or anti-inflammatory drugs, to avoid before the procedure.
• Shaving treatment area.Trimming and shaving is recommended the day before laser treatment. It removes hair above the skin that can result in surface skin damage from burnt hairs, but it leaves the hair shaft intact below the surface.

Hairs do not fall out immediately, but you will shed them over a period of days to weeks. This may look like continued hair growth. The repeated treatments are usually necessary because hair growth and loss naturally occur in a cycle, and laser treatment works best with hair follicles in the new-growth stage.

Results vary significantly and are difficult to predict. Most people experience hair removal that lasts several months, and it might last for years. But laser hair removal does not guarantee permanent hair removal. When hair regrows, it is usually finer and lighter in color.