By Celluline Inc, Toronto Laser Hair Removal Clinic,
Last update: 06/05/2015

About Laser Hair Removal Technology

What is the best and most efficient laser for hair removal?

 Most of the laser hair removal systems currently on the market can produce good long lasting results, and on this page we'll provide an overview of the basic principles of laser hair removal technology. To find out how to choose the laser that is most effective for you, click here.

Laser Hair Removal Technology

There are a number of devices on the market for laser hair removal. All of laser hair removal machine selectively target the  melanin in the hair follicle, disabling or destroying it. There are currently five types of lasers in use for laser hair removal and many other device and multifunctional machines used today for hair removal.

Laser hair removal techniques:

• Ruby
• Alexandrite
• Diode
• Nd:YAG
• Quick switched Nd:YAG

IPL -  Intense Pulsed Light and other multifunctional device list can be found in our table below.

 These lasers deliver an intense beam of light which is made up of a single wavelength or color. The light energy is absorbed by the pigment or melanin in the hair follicle. The follicle is thereby heated and injured, resulting in less hair growth. In addition, there are a variety of intense pulsed light systems (non-laser) in use for laser hair removal. These systems deliver light which is made up of multiple wavelengths or colors. There are also some multifunctional laser that combine laser with IPL or RF - radiofrequency.

Multifunctional lasers are popular in Spas or beauty salons, because they can perform many services including hair removal. Down site of multi functional lasers is that they do all but  they are master in none. Real lasers deliver an intense beam of light which is made up of a single wavelength and color.

Overview of Laser Hair Removal technology:

Ruby Laser: The 694nm ruby laser is very well absorbed by melanin, but its use is limited to patients with lighter skin. Ruby lasers work well for treatment of dark hair in fair-skinned patients. However, they are very limited in their ability to safely treat patients with darker or tanned skin. For this reason, other lasers have largely supplanted the ruby laser for laser hair removal.

Alexandrite Laser: The 755nm alexandrite laser is similar to the ruby, except that it has a greater penetration and less melanin absorption because of the slightly longer wavelength. Alexandrite lasers have been very popular in the past for laser hair removal. The Long Pulse Alexandrite Laser is best reserved for patients with light skin. The alexandrite laser is more safer than the ruby for treatment of darker skinned patients.

Diode Laser: Solid state 800nm diode lasers feature a longer wavelength and pulse width, offering an advantage in treating  darker skinned or tanned  patients as well as fair-skinned patients . The LightSheer obtained FDA approval for permanent hair reduction. The LightSheer diode laser has achieved the most worldwide widespread use for laser hair removal. This laser works well in fair-skinned patients, but has the added versatility to safely treat many darker or tanned patients. By extending the pulse duration to 100 milliseconds or beyond, diode lasers can effectively treat tanned or dark-skinned patients. Diode lasers appear to fall into the "sweet spot" in laser hair removal, allowing safe and effective treatment of the widest range of hair type and patient.

Q-Switched Nd:YAG: With a wavelength of 1064nm, relatively low melanin absorption, and skin penetration. The nanosecond-range  pulse width of the Q-Switched YAG and low energy (3 j/cm) is thousands of times too short to cause complete disruption of the hair follicle, resulting in prompt hair regrowth. In order to enhance absorption of energy, a suspension of carbon particles can applied before treatment, usually after hair removal by waxing, allowing the carbon suspension to penetrate into the follicle and conduct absorbed laser energy to the follicular structures, as in the Thermolase SoftLight system. Although safe for darker-skinned patients and effective for short term hair reduction, the Q-Switched Nd:YAG is generally considered the least effective laser for long-term hair reduction.

Long Pulse Nd:YAG long-pulse Nd:YAG lasers generate pulse widths that closely match the thermal relaxation time of hair follicles, and has recently been approved by the FDA for permanent hair reduction.  The Nd:YAG laser is the treatment of choice for patients with dark, coarse hair and dark skin, such as African-Americans. Compared to other lasers, the Nd:YAG laser may have reduced efficacy for treatment of finer, lighter hair, as there is less melanin absorption at the Nd:YAG wavelength.

Intense Pulsed Light - IPL  devices use xenon flashlamps to generate multiwavelength noncoherent light for hair removal and other applications. By using cut-off filters, only longer wavelengths in the range of 600-1200nm are passed through the handpiece, and pulsed singly or in pulse trains with variable delay between pulses. The parameters are software-controlled after entering the patient's skin type and hair characteristics. A chilled handpiece cools the skin and a transparent gel provides optical coupling as well as additional cooling.

 Skin is "transparent" in the 600-1100nm range, with melanin-bearing structures as the most attractive target for laser energy.

Melanin absorption decreases with increasing wavelength. Laser light at 694nm to 1064nm is absorbed by melanin, not only in hair but in epidermis, so epidermal melanin content limits the depth of penetration and energy fluence that can be used without unacceptable thermal injury to the skin.

Body hair chart:

Conclusion: Shorter wavelengths are better absorbed by melanin, but do not penetrate deeply into skin; shorter wavelength lasers are most effective in patients with darker hair and lighter skin.

Conversely, longer wavelengths penetrate more deeply, and are not strongly absorbed by epidermal melanin, causing little skin reaction, but higher fluences must be used to deliver sufficient energy to damage the hair follicles. In practice, longer wavelength lasers are safer for patients with darker skin, but in any case more energy can be delivered to the hair follicles if there is more melanin in the hair and less in the skin.

 Epidermal Cooling: All of these laser devices use  epidermal cooling to protect the skin from heating and decrease discomfort during treatment.

Cooling methods are:

• Cryogen:  Cooling with the cryogen spurts on the skin surface prior to delivering of laser pulse.
• Cooling gel:  A layer of cooled clear gel is applied before delivery of the laser pulses.
• Contact cooling: The LightSheer use a sapphire-cooled handpiece  (ChillTip) that is placed in direct contact with the skin.
• Cold airflow: The Apogee-40 laser uses a cooling handpiece (SmartCool) that allows a continuous flow of chilled air to the treatment area.

Lasers , IPL other multifunctional machines for Hair Removal overview:

Soprano - new Diode laser from Alma. It have promising technical characteristics but fail to deliver results. To read fool story click here
Soprano Before	Soprano After 5 treatment

Laser Hair Removal chart - cost, speed, pain, results and safety.

Aspects of Laser Hair Removal:

Before the laser treatment: Determine the patient's skin type and hair color. The differential absorption of melanin in the hair follicle and melanin in the epidermis determines the amount of energy that can be used safely.  Shorter wavelengths such as the ruby laser with 694nm and alexandrite laser with  755nm must be used with caution in darker (type IV-V) skinned patients, because of the risk of pain, blistering, and hypopigmentation. Dark hair absorbs laser light better than blond or red hair, and usually responds better-however, most patients with blond or red hair have lighter skin, allowing higher energies to be used safely. 800 nm diode laser with long pulse duration can treat all skin types. Aurora Laser (IPL and RF) manufactures claim that this machine can treat grey  and blond hair, but there is no evidence to support it. Other methods to treat red, blonde or grey hair with laser is to use topical skin spray Meladine.

 Laser Hair removal for Blonde, Red and Grey hair - with Meladine Treatment

How does it work?
Meladine is made up of natural melanin, which has been encapsulated into liposomes. When used daily, starting 14 days prior to lease treatment, the hair absorbs the natural melanine. The liposomes penetrate the hair providing a temporary target for the laser.

 It is recommended that the client uses the Meladine twice daily 14 days prior to laser hair removal treatment. It should be used before each treatment because the laser should have removed the hair previously treated with Meladine that was in the active growth phase.

Suggested Use for Fine, Soft, Vellus Hair:
1. Begin your daily Meladine™ routine 14 days prior to each laser treatment.
2. It is important that the hair be shaved or clipped daily. Do NOT wax, tweeze, or use depilatories on the area between treatments.
3. Always apply Meladine™ to clean skin. Do not use cosmetic preparations prior to application of Meladine™.
4. In the morning, spray the area to be treated with Meladine™, and allow to dry. Repeat this spraying and drying process 4-6 times. It is imperative that Meladine™ be allowed to dry between each spray. Hold sprayer 3-5 inches away from area to be treated.
5. Research has indicated that gently patting the Meladine™ into the skin before drying can help with absorption.
6. Repeat step 4 in the evening.

Skin type chart - Fitzpatrick skin phototypes:

Contraindications to Laser Hair Removal include  patients using photosensitizing medication such as Accutane, tetracycline, or Retin-A should discontinue the medication weeks, and for Accutane, months before treatment, and patients who are pregnant. There's no scientific evidence to suggest that laser light used in hair removal can injure a fetus, but the treatment should be avoided just as precaution. Patients who are tanned should wait for the tan to fade for best results.

Preparation: Hair should not be plucked or waxed before treatment. This removes the hair shaft from the follicle, thus removing most of the melanin chromophore. Do not shave hair before first treatment because it laser technician have to  determine the hair color for treated area. Hair may be shaved after first session to speed up treatment. Lotions, cosmetics, and other skin preparations should be avoided on the day of treatment.

Treatment: Details may vary slightly with each device, but all the techniques involve the even application of laser energy over the treatment area, with some mechanism to cool the epidermis to allow a higher fluence to target the follicle. The speed of coverage depends on the spot size of the beam or scanning pattern, operator fatigue, and patient comfort.  Discomfort can be minimized by topical anesthetic creams (Emla).

 Laser Hair Removal Efficiency:  Laser does not  destroy all of the hair follicles. Some follicles are destroyed, others are miniaturized into vellus hairs, and some are shocked into prolonged dormancy. Multiple treatments are needed for best results, and the best interval for treatment is when new hair regrowth is observed, usually 6 to 12 weeks after the first treatment, and 3 to 6 months after the second treatment. In most cases there will be visible improvement within a week after the first treatment.

©  Celluline Inc.