Laser hair removal is a technique for permanent hair removal because laser energy is used to destroy hair follicles. Follicles destroyed by laser energy will never again produce hair. Electrolysis is the only other method of hair removal that permanently stops the growth of hair. Laser hair removal is not permanent in all people who are treated, however. Hair regrowth occurs in some cases despite repeated treatments.
Laser hair removal works only on brown and black hair. It does not work on blond, red, gray or white hair.
Laser hair removal can be performed on any part of the body.
How It Works
Laser hair removal is based on the principle that wavelengths of laser light are selectively absorbed by a target material. For hair removal, laser wavelengths are absorbed by melanin, the coloring pigment of hair (see Hair Color: Biology, Mythology and Chemistry). When the intense laser energy beam is absorbed by melanin, the melanin transmutes laser energy into heat energy. The heat energy destroys all (or most) melanin-containing cells in the hair and hair follicle.
A physicist working in laser development once wrote that it was Albert Einstein who established the basic principle of lasers, and Darth Vader who brought lasers to the attention of the public.
LASER is an acronym standing for Light Amplification by Stimulated Emission of Radiation. It was Albert Einstein who established the basic principle of lasers:
When the electrons of an atom are excited to a higher energy state, they will eventually return to their original resting state by emitting a photon (packet) of electromagnetic radiation. The wavelength of this released radiation is also expressed as a "color" in the electromagnetic spectrum.
Scientists subsequently built upon the Einstein principle to show that atomic electrons can be purposely "pumped" to elicit a specific wavelength or "color" of very pure (coherent) electromagnetic energy. The result is a beam of very pure coherent wavelength, unlike any light existing in nature. The atoms to the "pumped" (the lasing medium) are present in a gas, liquid, crystal or ionized metal. The "pumping" energy is delivered by electricity, radiofrequency waves, a flash lamp or chemical reaction. The lasing medium is contained in an "optical cavity"-a tightly sealed container with mirrors at both ends to assure amplification of the energy elicited by "pumping". The laser is "fired" by halting the pumping and allowing the atomic electrons to return to their original resting state-in the process, emitting the radiation specific to their "pumped" energy state.
Many of the medical uses of lasers are based upon the monochromatic nature of laser light-that is, its very pure "color". By selectively matching lasing medium (for example, a ruby crystal) to pumping energy, a laser beam of specific wavelength (color) can be produced. This beam of specific color can be directed upon a target that will specifically absorb the laser beam energy and transmute the electromagnetic energy into heat energy that will destroy a target tissue.
Other features of laser energy-its purity and coherence-are used in medicine to achieve other purposes such as penetration of tissue to deeper levels in laser surgery and cancer treatment.
Lasers currently used for hair removal use light wavelengths that target eumelanin, the coloring pigment of brown and black hair. Dark hair of large cross-section ("coarse hair") has rendered the best results from laser removal. Because pheomelanin, the relatively colorless coloring pigment of blond and red hair is not affected, red and blond hair cannot be removed by laser treatment. Newer technology used in Intense Pulsed Light (IPL) instruments creates a range of wavelengths rather than a coordinate beam of a single wavelength; IPL technology offers the possibility of targeting a variety of melanin hues.
How It Is Done
The hair removal laser or IPL generator is contained in a box-shaped instrument. The instrument is pressed firmly against the skin where hair is to be treated. Pressing the instrument firmly against the skin assures that (1) all of the laser energy is focused upon the treatment site, and (2) prevents accidental leakage of laser light into the environment where it could damage someone's eyes even in an adjoining room. During laser treatment, the eyes of the treating physician and assistants are protected by goggles and the patient's eyes are protected by goggles or covered with opaque patches.
How a laser hair removal session is conducted is influenced by characteristics of the individual patient-for example, hair pigmentation, skin color, skin thickness and any previous skin conditions. The number of laser pulses directed at a specific site to assure adequate "kill", the number of sites treated at one session, and the duration of a session can all be influenced by patient characteristics.
Laser hair removal is a medical procedure. As with preparation for any medical procedure, the patient undergoes a physical examination and is questioned regarding medical history and medications currently being taken.
Side Effects, Outcomes and Cost
Hair removal by laser or IPL treatment usually requires several sessions to realize the optimal result. Sessions are scheduled several weeks apart. The same sites may be treated several times to assure maximum "kill" of hair follicles. Some follicles are destroyed by treatment but others may be resistant to laser treatment and require multiple procedures.
Laser hair removal is permanent for some patients; other patients may experience regrowth of hair from treatment-resistant hair follicles, or if the procedure was performed by an operator with inadequate training in laser hair removal.
Side effects of laser hair removal may include:
- Unpleasant warmth at a site being treated, a side effect alleviated by cooling with air or a spray;
- Post-treatment lightening or darkening of skin at treatment sites-usually temporary; and,
- Rarely, post-treatment oozing and crusting at a treatment site.
Cost of laser hair removal varies greatly, depending on variables such as number of sessions required. Cost should be discussed with the physician before treatment is undertaken. The patient should find out, before treatment, whether medical insurance will cover all or part of the treatment cost.