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Hair removal has become popular even among younger generations and men. For those prone to irritant dermatitis, folliculitis, or chronic pyoderma due to shaving, hair removal is also recommended.

Since I'm often asked about hair removal types and suitable ages, I'd like to summarize the different hair removal methods and their suitability here.

I am Dr. Aya Hayama, a board-certified dermatologist.

 

Types of Hair Removal

 

Medical hair removal works by directing laser energy at the dark pigment (melanin) in hair, converting it into heat, and using that heat to destroy the cells that produce hair, preventing regrowth. Technically known as the "selective photothermolysis theory," this method efficiently targets and heats only the hair. However, since skin also contains melanin, individuals with darker skin tones absorb more laser energy, increasing the risk of burns. Therefore, selecting the appropriate laser based on skin type, age, and gender differences is crucial.

There are various types of hair removal,Medical laser hair removal, light-based hair removal, needle hair removal, wax hair removalThese are representative methods. Furthermore,Among medical lasers: Alexandrite, Diode, Nd:YAG, and thermally-basedThere are multiple types, each with different effects and suitability for different skin types.

 

MedicalFour Types of Laser Hair Removal and Their Features

 

There are primarily four types of medical laser hair removal, each with distinct characteristics based on differences in wavelength.

Alexandrite Laser (755nm)Laser light is strongly absorbed by hair melanin, making it particularly effective on dark hair against fair skin. However, on darker skin tones, it also reacts with the skin, increasing the risk of burns.Diode laser (800–810 nm)It is said to offer an optimal balance between penetration depth and melanin absorption, making it most suitable for Asian skin types, including Japanese.Nd:YAG laser (1064 nm)It penetrates deep into the skin and is less likely to be absorbed by surface melanin, making it safe for use on darker skin tones and tanned skin. However, this also means its reaction to hair is somewhat weaker, and it may take longer to see results.Heat-accumulating laser (primarily around 810nm, SHR method)This method gradually warms the entire hair follicle by repeatedly applying low-energy pulses, rather than delivering intense heat all at once as in conventional methods. It features reduced risk of pain or burns and is well-suited for darker skin tones and fine vellus hair.

 

Age-related characteristics

 

The effectiveness of hair removal also varies depending on age.During the teenage years, hair growth is unstable due to hormonal influences, so hair tends to regrow easily even after removal.There is a tendency. People in their 20s and 30s have stable hormone levels, making this a period when hair removal effects are easily achieved.For women in their 40s and beyond, body hair may become thinner, while new hair growth may appear around the mouth and other areas.Men tend to retain thick hair even as they age, and beard hair removal in particular requires high power settings and multiple sessions. As people get older, skin recovery slows down, so redness and hyperpigmentation after laser treatment tend to last longer, necessitating careful adjustment of settings.

Gender differences are also a major factor. Men's hair is thicker and grows from deeper follicles, requiring higher energy levels for treatment compared to women. Areas like facial hair and chest hair take longer to show results. Conversely, women have finer hair and more vellus hair. Combining Alexandrite or diode lasers with heat-accumulating lasers effective on vellus hair yields good results. For both genders, areas highly influenced by hormones (around the mouth and VIO) may require additional treatments.

 

About IPL Hair Removal

 

IPL hair removal is,Unlike medical lasers, this method damages hair follicles using light with a broad wavelength range of approximately 500 to 1200 nm.is.Often performed at esthetic salons, etc.The output is weaker than medical lasers, resulting in less pain and reduced burden on the skin. However, the effects are correspondingly milder,Permanent hair reduction effects are limited.It is considered a treatment that aims for changes such as "thinner hair growth" or "slower hair regrowth," rather than complete hair removal. While it is easy to start for cosmetic purposes, medical laser hair removal is more suitable for those seeking reliable results or permanent hair removal.

 

The Difference Between Light-Based Hair Removal and Medical Laser Hair Removal

Both light-based hair removal and medical laser hair removal target the melanin pigment in hair to damage the hair follicles, but their mechanisms and effects differ significantly. IPL hair removal uses broad wavelengths at low output, resulting in minimal pain and gentler treatment for the skin. However, because the energy is dispersed, the effects are mild, making it closer to temporary cosmetic care. In contrast, medical lasers utilize wavelengths such as Alexandrite (755nm), Diode (800-810nm), and Nd:YAG (1064nm).Single wavelengthBy delivering high-energy density irradiation, it can effectively inflict thermal damage on the hair follicle papilla and bulge region. As a result, long-lasting and reliable hair reduction effects are achieved,It is also recognized by the U.S. FDA as "permanent hair reduction."。

 

Differences in suitability based on skin type and race, such as Caucasian and African American

 

Since our hospital treats many patients from various countries, I would like to address this point as well.

Adaptation also varies depending on race and skin color. For individuals with fair skin and dark hair, such as Caucasians, Alexandrite lasers and diode lasers are highly effective. Conversely, for individuals with high melanin levels in the skin, such as African Americans, the shorter wavelength Alexandrite laser carries a high risk of burns and is considered unsuitable. The Nd:YAG laser, which is less easily absorbed by epidermal melanin, is recommended instead.

According to a report published in the Journal of the American Academy of Dermatology, the Nd:YAG laser is most highly recommended as a safe and effective hair removal method for skin types IV to VI (commonly referred to as dark to black skin).On the other hand, it has been reported that the Alexandrite laser demonstrates the highest hair removal effectiveness among individuals with relatively fair skin, including Caucasians and Asians.

 

Methods other than medical laser and light hair removal

 

As for methods other than medical lasers,Needle hair removalとWaxingThere is.

Needle hair removal involves inserting a thin needle into the hair follicle and applying an electric current to directly destroy the cells that produce hair. It is the only method effective for gray hair and fine hair, which are difficult to treat with lasers. However, it is time-consuming because each hair is treated individually, and it presents challenges in terms of pain and cost.

Waxing is a method that involves applying specialized wax to remove hair from the root in one swift motion. However, since it does not destroy the cells that produce hair, regrowth occurs within a few weeks, and long-term results cannot be expected. It is often used for temporary hair removal before events or similar occasions and is typically performed at esthetic salons.

 

Estimated Number of Sessions and Duration for Hair Removal

 

Medical laser hair removal does not permanently remove hair in a single session.Hair has a growth cycle consisting of the anagen phase, catagen phase, and telogen phase.、Laser treatment is most effective on hair in the growth phase.Therefore, it is necessary to repeat the irradiation in multiple sessions.

Generally, most people find 8 to 10 sessions sufficient for facial peach fuzz, while areas with thicker hair like the underarms and bikini line typically require 5 to 6 sessions. Treatments are scheduled every 1 to 2 months to align with the hair growth cycle, and completing full-body hair removal generally takes about one to one and a half years.

Needle hair removal treats each hair individually, making it difficult to complete large areas quickly. However, it is effective for small amounts of white hair and hair that is unresponsive to laser treatment. Waxing produces a beautiful result immediately after treatment, but hair regrows within a few weeks, requiring ongoing maintenance.

 

Potential Side Effects to Be Aware of with Hair Removal

 

While hair removal can be highly effective, it may also cause side effects. Temporary redness or swelling from the treatment is not uncommon, and in rare cases,Burns and hyperpigmentationIn some cases, hair regrowth may become thicker and coarser."Coarse Hair Growth"A phenomenon known as *3 may occur, particularly in areas with abundant vellus hair such as the back and upper arms. While these reactions do not necessarily happen frequently, understanding this possibility can provide peace of mind.

 

The hair removal method that suits you best

Hair removal methods include medical laser, light-based hair removal, needle epilation, and waxing, each with its own advantages and disadvantages. For those seeking reliable results, medical laser is recommended. Needle epilation is effective for gray hair and fine hairs. For those wanting a convenient temporary solution, light-based hair removal or waxing are suitable options. Choosing a method that aligns with your goals and skin type is crucial.