HAIR REMOVAL TREATMENTS
Laser hair removal is the process of removing unwanted hair by means of exposure to pulses of laser light that destroy the hair follicle. It had been performed experimentally for about twenty years before becoming commercially available in the mid-1990s. One of the first published articles describing laser hair removal was authored by the group at Massachusetts General Hospital in 1998. Laser hair removal is widely practised in clinics, and even in homes using devices designed and priced for consumer self-treatment. Many reviews of laser hair removal methods, safety, and efficacy have been published in the dermatology literature.
How it works
The primary principle behind laser hair removal is selective photothermolysis (SPTL), the matching of a specific wavelength of light and pulse duration to obtain optimal effect on a targeted tissue with minimal effect on surrounding tissue. Lasers can cause localised damage by selectively heating dark target matter, melanin, thereby heating up the basal stem cells in the follicle which causes hair growth, the follicle, while not heating the rest of the skin. Light is absorbed by dark objects but reflected by light objects and water, so laser energy can be absorbed by dark material in the hair or skin, with much more speed and intensity than just the skin without any dark adult hair or melanin.
Melanin is considered the primary chromophore for all hair removal lasers currently on the market. Melanin occurs naturally in the skin and gives skin and hair their color. There are two types of melanin in hair. Eumelanin gives hair brown or black color, while pheomelanin gives hair blonde or red color. Because of the selective absorption of photons of laser light, only hair with color such as black, brown, or reddish-brown hair or dirty blonde can be removed. White hair, light blonde and strawberry blonde hair does not respond well. Laser works best with dark coarse hair. Light skin and dark hair are an ideal combination, being most effective and producing the best results, but lasers such as the Yag laser are able to target black hair in patients with dark skin with some success.
Hair removal lasers have been in use since 1997 and have been approved for “permanent hair reduction” in the United States and the United Kingdom by the Food and Drug Administration (FDA). Under the FDA’s definition, “permanent” hair reduction is the long-term, stable reduction in the number of hairs regrowing after a treatment regime. Indeed, many patients experience complete regrowth of hair on their treated areas in the years following their last treatment. This means that although laser treatments with these devices will permanently reduce the total number of body hairs, they will not result in a permanent removal of all hair.
Laser hair removal has become popular because of its speed and efficacy, although some of the efficacy is dependent upon the skill and experience of the laser operator, and the choice and availability of different laser technologies used for the procedure. Some will need touch-up treatments, especially on large areas, after the initial set of 3-8 treatments.
Comparisons with other removal techniques
Comparison with Intense Pulsed Light
A 2006 review article in the journal “Lasers in Medical Science” compared intense pulsed light (IPL) epilators and both Alexandrite and Diode lasers. The review found no statistical difference in short term effectiveness, but a higher incidence of side effects with Diode laser based treatment. Hair reduction after 6 months was reported as 68.75% for Alexandrite lasers, 71.71% for Diode lasers, and 66.96% for IPL. Side effects were reported as 9.5% for Alexandrite lasers, 28.9% for Diode lasers, and 15.3% for IPL. All side effects were found to be temporary and even pigmentation changes returned to normal within 6 months.
IPL, though technically not containing a laser, are sometimes incorrectly referred to as “laser hair removal”. IPL-based methods, sometimes called “phototricholysis”, or “photoepilation”, use xenon flash lamps that emit full spectrum light. IPL systems typically output wavelengths between 400 nm and 1200 nm. Filters are applied to block shorter wavelengths, thereby only utilizing the longer, “redder” wavelengths for clinical applications. IPLs offer certain advantages over laser, principally in the pulse duration. While lasers may output trains of short pulses to simulate a longer pulse, IPL systems can generate pulse widths up to 250ms which is useful for larger diameter targets. Some current IPL systems have proven to be more successful in the removal of hair and blood vessels than many lasers.
Comparison with electrolysis
Electrolysis is another hair removal method that has been used for over 135 years. Like newer laser technology used properly and with several treatments, electrolysis can be used to remove 100% of the hair from an area and is effective on hair of all colors, if used at an adequate power level with proper technique. But the treatment is very slow and tedious compared with typical newer laser hair removal. More hair may grow in certain areas that are prone to hormone-induced growth (e.g. a woman’s chin and neck) based on individual hormone levels or changes therein, and one’s genetic predisposition to grow new hair.
A study conducted in 2000 at the ASVAK Laser Center in Ankara, Turkey comparing Alexandrite laser and electrolysis for hair removal on 12 patients concluded that laser hair removal was 60 times faster, less painful and more reliable than electrolysis. It is important to note that the type of electrolysis performed in the study was galvanic electrolysis, rather than thermolysis or a blend of the two. Galvanic current requires 30 seconds to more than a minute to release each hair whereas thermolysis or a blend can require much less. This study thus did not test the capability of all forms of modern electrolysis.