Say goodbye to Alexandrite. It’s time to find a new option suitable for Asian’s skin tone and hair color
Laser hair removal treatment has become very common for more than two decades. There is a wide spectrum of laser devices available in the market, such as diode laser (755nm to 1064nm), Nd:YAG laser (1064 nm), Alexandrite laser (755 nm), and ruby laser (680 nm).
In the early phase of applying laser for hair removal treatment, it is mostly suited for patients with fair skin tone (Fitzpatrick I-II); however, Treatment to darker skin tone could cause complication such as thermal damage and hyperpigmentation.
Alexandrite Laser Versus Diode Laser
As we know, hair color and skin tone are the key factors to effective hair removal. Asians generally have relatively darker skin tone, usually type IV in Fitzpatrick phonotype scale according to dermatology research.
Melanin has high absorption at the wavelength of 755nm. The principle is that the melanin in hair follicle absorbs laser beam and therefore being destroyed, the stem cells attached with hair follicles are destroyed as well. It would effectively disable hair growing. For example, the Alexandrite laser of 755 wavelength is wildly used for its excellence in dealing hair removal with light-colored patient with pale skin tone (Fitzpatrick Scale I & II).
However, we should pause here and start to consider if alexandrite laser really a good choice for treating all kinds of skin type.
The key is all about the epidermal melanin. Pale skin contains fewer melanin in the epidermis; hence it is less likely to be burned when laser beam penetrates through.
When we conduct hair removal, it should only be the melanin in hair follicles absorbs the laser energy but not the melanin in skin. Therefore, only the hair follicle would be destroyed but not the superficial skin getting burned.
The755nm wavelength of alexandrite laser can penetrate deep enough for heating up the hair follicle yet without burning the superficial skin. When containing much fewer melanin in their skin, it is less likely to be burned during treatment. That’s why alexandrite laser is more for pale skin tone and light-colored hair, instead of black hair and skin containing more melanin.
Diode Laser Proved as More Effective and Safer
Research has it that the treatment result can be very different when applying diode laser or alexandrite laser toward darker skin type.
A research in 2014 has compared 755nm Alexandrite laser with 810nm Diode laser for the efficacy and safety of hair removal treatment. It is indicated that 810nm diode laser is safer to treat darker skin without risk of epidermal burning. It’s also proven to be more effective than alexandrite to darker skin.
According to a research in 2005, it shared the similar result as above that diode laser surpasses both alexandrite laser and ruby laser in hair removal. The research has recorded 171 female hirsutism patients in Fitzpatrick skin types II- IV and followed their treatment for 12 months. Concerning the hair reduction and re-growth, it is observed that diode laser achieves better result followed by alexandrite laser and ruby laser. Diode laser treatment comes with least complication as well.
It is clearly proven that diode laser can deals with colored-skin and darker skin tone patients with efficacy and safety.
|Laser Type||Diode Laser
Long Pulse Laser
|755nm Alexandrite Laser|
|Penetration||Wide range of penetration||Deep penetration||Shallow penetration|
|Melanin Absorption||Wide range of melanin absorption||Low melanin absorption: requires more energy||High melanin absorption but easily burn darker skin|
|Treatment Comfortness||Medium painful.
Comfort increased with cooling system
Asian Skin Tone with Great Varieties
We should also consider more of the skin tone varieties. Asian is only a vague geographical idea but actually contains a wide variety of ethnicities in this area, from pale skin (Fitzpatick I & II), medium skin (Fitzpatick III & VI) to darker skin (Fitzpatick V&VI and more).
Single wavelength of merely 810nm is not enough. Usually the device would come in 2 or 3 wavelength combination. Take Smedtrum diode laser system ST-800 for example, it goes with 3 different wavelengths as 755nm, 810nm and 1064nm.
●The 755nm wavelength
The melanin absorption is the highest among the three wavelengths; hence it is specifically ideal for pale skin tone and light-colored hair (Fitzpatrick Skin type I, II, III).
●The 810nm wavelength
It’s also known as the “Golden Standard Wavelength,” suitable for all skin types, and much safer for people with darker skin color, as well as ideal for arms, legs, cheeks and beard.
●The 1064nm wavelength
It has a lower melanin absorption but deeper penetration to the dermis layer without damaging stratum corneum and epidermis; that makes it ideal for dealing with the darkest and thick hair or with the darkest skin or tanned skin person (Fitzpatrick Skin type III-IV tanned, V and VI).
Mustafa, F. H., Jaafar, M. S., Ismail, A. H., & Mutter, K. N. (2014). Comparison of Alexandrite and Diode Lasers for Hair Removal in Dark and Medium Skin: Which is Better?. Journal of lasers in medical sciences, 5(4), 188–193.
Saleh, N., et al (2005). Comparative study between ruby, alexandrite and diode lasers in hirsutism. Egyptian Dermatology Online Journal. 1:1–10.
Knaggs, H. (2009). Skin aging handbook: Skin Aging in the Asian Population. New York: William Andrew Inc. Pages 177-201.
Post time: Jul-03-2020