|This would suggest that perhaps there is more to simply ‘zapping’ the hairs with the right wavelength; the aim of targeting hair with broadband light devices such as IPL, is to attract heat to the hair shaft and hair bulb creating excessive heat, the aim is to destroy the function of the hair itself.
In order to do this successfully the targeted hair must be able to attract the light – namely it must do this by simple and non-negotiable science. If you park a black car and a white car in a car park on a hot sunny day and return to the cars an hour later, which car feels hotter?
The on-going speculation of this type of device for use on light, white, red and grey hairs is a constant one, often the subject of debate at medical conferences; each physician adopts their own conclusion based on results. Worth mentioning those facilities usually have multiple lasers and IPL devices in order to provide a range of treatments in order to satisfy the client’s expectations. This is often not the case here in New Zealand as the market here is considerably smaller, and the outlay for such a wide range of devices in a single clinic is almost unheard of.
Currently there are countless devices available for hair removal, one recently promoted device claims to be able to selectively target the blood supply at the base of the hair follicle, in order to destroy the hair, so theoretically it doesn’t matter what colour the hair is. Consequently this raises two main issues that must be addressed; the first one is the broadband light wavelengths ability to reach the base of the hair follicle (namely 2-5mm deep). This may pose an issue as IPL light has a restricted reach of depth due to the high degree of scatter at the surface of the skin. This scatter occurs naturally as a result of other targets completing for absorption; i.e.: melanin. Secondly, the wavelength must be of the correct co-efficient absorption that it can effectively target the chromophore (in this case blood) which is universally agreed at between 500 and 600 nm.
One more point must be discussed and that is the type of hair; vellus hairs being finer and naturally lighter than terminal hairs which also grow more superficially (1-2mm). Hence it is logical that most light, white or fairer hairs are in fact vellus hairs. To some degree these hairs will fall out with any IPL system due to the extremely fine nature of their structure. It would be wise at this point to state the saying ‘ under promise and over deliver’, as clients who seek a long term reduction in these hairs may need other treatment options in combination for ultimate results. For example: alkaline wash or electrolysis.
|The occurrence of terminal white, grey or red hairs would indeed prove more of a challenge to IPL devices regardless if they claim to be able to treat these hair colours or not. The test then would be to propose that suppliers of these devices provide evidence that white, grey or red terminal hairs (i.e.: pubic region, chin or underarms) are being destroyed; and that the hair is not simply being forced into a ‘prolonged dormancy’ stage where enough heat is generated to damage the upper portion of the hair shaft causing it to fall out, but leaving behind the hair bulb, which in turn slowly regenerates and the hair returns in due course. We note that most ‘clinical studies’ are only a short period, not sufficient enough to show long term effects.
The occurrence of terminal white, grey or red hairs would indeed prove more of a challenge to IPL devices regardless if they claim to be able to treat these hair colours or not. The test then would be to propose that suppliers of these devices provide evidence that white, grey or red terminal hairs (i.e.: pubic region, chin or underarms) are being destroyed; and that the hair is not simply being forced into a ‘prolonged dormancy’ stage where enough heat is generated to damage the upper portion of the hair shaft causing it to fall out, but leaving behind the hair bulb, which in turn slowly regenerates and the hair returns in due course.
Example extracts from summaries of clinical papers:
Diode laser with Radio frequency – Rafael A.Schulze, Brooke Harrison, and E. Victor Ross:
“There was a mean 50% in hair reduction after an average of 1.9 treatments with a mean follow up of 2.7 months’, there was a trend towards greater hair reduction with thicker and darker hair, although in two cases there was a marked reduction in thinner hairs.” “There was no observed differences between low and high radiofrequency energies. Pain was proportional to hair pigmentation, density and thickness, and occasionally was severe.”
CAREEN A. SCHROETER1, SAPNA SHARMA1, NGOZI C. MBONU1, THORSTEN REINEKE2 & HERMAN A. M. NEUMANN 31 Department of Lasertherapy, Medical Centre Maastricht, Maastricht, The Netherlands:
“Seventeen patients with blond hair were randomly selected from the Department of Lasertherapy, Medical Centre Maastricht, The Netherlands.” : “The aim of this study was to test blond hair removal using the ELOS system, which is optical energy and radio-frequency combined”. “Results: A mean hair reduction of 57.4% was obtained with a mean of 8.5 treatments.”
Adéna Device – Laboratoire DERMSCAN, France (Feb 2011):
“On all subjects, the photo-depilation sessions allow to significantly decrease the hair density as of the first session (-55% on average). More precisely, a decrease of 72% on average of the density of the dark hair (black or brown) and 41% of the light hair (white or blonde) was observed.”
From clinical observations chart provided on this study we see at post 4 sessions ‘white and blonde’ hair has reduced by -36%, yet the dark hairs have reduced by -75%. Two subjects dropped out due to burns to the epidermis although the skin type was light.
In conclusion we see that clearly wavelengths produced from a broadband IPL device are not the only matter for consideration, the ability for the device to penetrate the skin at the efficient amount of energy, whilst providing sufficient cooling to protect the epidermis from burns, all the while taking into account the colour of the skin and competing chromophores unsurprisingly limits the results. Many devices make significant claims and their outputs do have some shortcomings with regards to safety on the skin types advertised, or sufficient power to generate enough heat. Clinics choosing to venture into the controversial hair reduction must first be educated in the ability to ask the right questions of the supplier, and not be bamboozled by the technical responses or so called clinical papers which often are cleverly worded. The suggestion of a thorough trial of any proposed system would be advised; such as asking to treat your own models with the lightest possible hair and / or the darkest skin types possible at the highest possible efficacious fluences (energy); prior to making final purchase decisions. Asking for multiple images of blonde subjects after 12 months of treatment with the said device may prove to be ‘unavailable’, thus leading to a somewhat questionable surmise.
a Ilyin, Natalia. 2000. Blonde Like Me: The Roots of the Blonde Myth in Our Culture. New York, NY: Simon & Schuster. Gregory B. Altshuler, PhD; Ilya Yaroslavsky, PhD, Palomar Medical Technologies, Burlington, MA
Various clinical papers from leading laser & IPL suppliers.