Laser Hair Removal

Laser hair removal is a medical procedure that uses a focused beam of light, known as the laser, to eliminate unwanted bodily hair. During the process of laser hair removal, a laser emits light that is absorbed by the pigment (melanin) in the hair. This light energy is then consequently transformed into heat, which then damages the tube-shaped sacs (hair follicles) responsible for hair production within the skin. This process disrupts and postpones future hair growth. While laser hair removal manages to effectively delay hair growth for prolonged periods, it generally does not achieve permanent hair loss. Multiple laser hair removal sessions are often necessary for the initial removal of hair, with ongoing maintenance sessions as needed. 

Typical sites for treatment with laser hair removal include the legs, armpits, upper lip, chin and bikini line. However, virtually any area with unwanted hair can be treated, excluding the eyelids and immediately surrounding regions. Furthermore, any skin that has been tattooed should also be excluded from treatment with lasers. The efficacy of this procedure is heavily influenced by hair color and skin type. The fundamental principle for laser hair removal states that the laser should be absorbed by the pigment of the hair, NOT by the pigment in the skin. The objective is to damage solely the hair follicle while safeguarding the skin from any harm. Therefore, optimal results from laser hair removal are achieved when there is a contrast between the color of the hair and skin. 

In terms of the technology that is used to complete this procedure, there are an array of different lasers and IPL (intense pulsed light) systems that are accessible and are generally the most effective choices for achieving long-term hair reduction. The mechanism of action of these machines is directing light specifically to the melanin in the hair shaft, follicular epithelium, and hair matrix, emitting wavelengths typically ranging between 600 to 1200 nm. This is because these particular wavelengths are selectively absorbed by the melanin found in the hair shaft, thus facilitating the desired results. The type of laser that is used on an individual patient should be decided based upon their Fitzpatrick skin types, ranging from level I to level VI: 

I: fair complexion, blue/green eyes, blond/red hair, prone to sunburn, lacks ability to tan

II: light skin, blue eyes, prone to sunburn, doesn’t tan well

III: fair skin that tans after initial sunburn

IV: light brown skin that experiences minimal burning and tans effortlessly

V: brown skin, seldom burns, readily tans to a darker shade 

VI: dark brown to black skin, never burns, always darkens when tanning 

The lasers available for different types of skin with varying wavelengths include the following: 

1. Ruby laser (694 mm): red light is delivered via synthetic red crystals , effective for individuals with light skin tones and dark hair (skin types I to III)

2. Alexandrite laser (755 nm): offers a deeper penetration than the Ruby laser, suitable for lighter hair (skin types I to III)

3. Diode laser (810 nm): penetrates more deeply, provides improved fluence, reduces epidermal damage, safer for darker skin tones (skin types I to V)

4. Neodymium-doped Yttrium-Aluminum-Garnet (Nd:YAG) laser (1064 nm): improved penetration, reduced epidermal damage, relatively lower melanin absorption, suitable for a wide range of skin types (types I to VI)

5. Intense pulse light (IPL) or Broadband light (BBL) (500-1200 nm): flash-lamp delivers high-intensity pulses of polychromatic, non-coherent light. Through the use of various filters, the emitted wavelength band can be narrowed. This method is appropriate for darker skin tones and covers larger areas at once due to its larger spot size. 

Aftercare post-laser hair removal often includes ice packs or cooling agents may be applied after the procedure to reduce discomfort and swelling. In the event of accidental skin injuries, topical antibiotics may be prescribed as needed. Stringent sun protection and the application of sunscreen are also highly recommended for post-procedure care. The most common side effects of laser hair removal are blisters, burns, hyper- or hypopigmentation and scarring. 

Resources: 

Vaidya T, Hohman MH, Kumar D D. Laser Hair Removal. [Updated 2023 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507861/

Laser Hair Removal. Mayo Clinic. March 13, 2024. Accessed May 2, 2024. https://www.mayoclinic.org/tests-procedures/laser-hair-removal/about/pac-20394555. 

Laser hair removal: What is it, procedure, safety & side effects. Cleveland Clinic. September 1, 2021. Accessed May 2, 2024. https://my.clevelandclinic.org/health/treatments/21757-laser-hair-removal.