Laser Hair Removal
IPL Hair Removal

Laser hair removal has been in common use since the late 1990s. It is one of the most popular procedures performed in cosmetic clinics. Almost everyone has either had the procedure or knows someone who has. This is an area of cosmetic dermatology that is not the least bit questionable. It works, the bugs have all been worked out, and there are now many very experienced laser practitioners.

In this article, I'll teach you the basics of laser hair removal.

We will also discuss intense pulsed light hair removal.

In much of the article, I refer to "laser", when in fact, I am referring to lasers and IPL devices. There are definitely differences between laser and IPL, and I will point these out.



What is laser hair removal and how does it work?
Laser hair removal involves the application of powerful light (delivered by laser or IPL [intense pulsed light]) to eliminate unwanted hair from any part of the body. The light penetrates the skin and is absorbed by pigment (melanin) in the root of the hair. Instantaneously, the temperature of the hair rises beyond the burning point. This burning hair damages the cells of the follicle that produce the hair. Because the light energy is absorbed primarily by the hair root, the skin is undamaged.

If sufficient damage has been done to the hair follicle, it dies and will not regenerate. Voila! Permanent hair removal!

What is the best laser for laser hair removal?
Unfortunately, there is no simple answer to this. The bottom line is that there is no such thing as "the best laser". Life is full of compromises, and laser hair removal is no exception.

Let me explain (this is going to get a bit long-winded and scientific, but bear with me. I'll try to make it simple.)

The target for laser light energy is the pigment called melanin. This pigment is found in hair and throughout the skin. The darker your hair or skin, the more melanin it contains. The object of laser hair removal is to have more absorption of laser light energy by the melanin in the hair root than by melanin in the skin, thereby burning the hair and destroying the follicle but preserving the skin. When melanin in skin absorbs too much energy, the result is burning and pigment changes.

The best target is black hair and pale skin. Black hair is easy to burn (lots of melanin and lots of light absorption). Pale skin is difficult to burn (very little melanin and poor light absorption).

The compromises start to come into play as skin gets darker and hair gets lighter.

Lasers all shoot light at a single wavelength (color).Different lasers have different wavelengths, and these different wavelengths behave differently.

Long wavelengths have poor absorption by melanin and high penetration into the skin.Short wavelengths have good absorption by melanin and low penetration.

When a long wavelength laser is used, not much energy is absorbed by the melanin in skin or in the hair, but the high penetration means that there is more light energy available at the hair root to be absorbed. Conversely, when short wavelength laser is used, not much light gets to the bottom of the hair follicle, but what does arrive is very well absorbed. The two factors average out and, therefore, all lasers will do the job of hair removal.

However, there is a major difference in safety. The longer the wavelength, the poorer the absorption by melanin in the skin, and therefore the greater the safety.

The cutoff line for safety in all skin colors is at about 800 nanometers. The NdYAG laser has the longest wavelength available for hair removal (1064 nanometers). The longer wavelength of the laser results in less light energy being absorbed in the skin. It is the safest device available for laser hair removal. The longer wavelength of NdYAG lasers is safe for use on all skin colors.

Shorter wavelengths of light are scattered and absorbed in the very superficial layers of the skin where they may cause undesirable skin side effects such as burning and pigment changes. These shorter wavelengths are unsuitable for treating tanned or dark skin, but work very well in light-colored skin. Shorter wavelength lasers also have an advantage in treating lighter colored hair, because these wavelengths are better absorbed by the lesser amount of melanin contained in this hair.

IPL devices belong to the short wavelength category. They emit many colors (wavelengths) of light, most commonly at about 650 nm and up. The lower wavelengths are better absorbed by lighter colored hair. The tradeoff is that IPL can only be used in fair skinned people. Fortunately, these are also commonly the people who want to eliminate lighter colored hair.

Bottom Line: Long wavelength lasers are safe and effective for all skin colors and darker hair. Short wavelength lasers and IPL devices are safe and effective for a wider range of hair colors in people with lighter colored skin.

What are some of the common lasers and IPL devices in use for hair removal?

In descending order from long to short wavelength:

NdYAG at 1064nm:

CoolGlide by Cutera (formerly Altus)

Lyra by Laserscope

Profile by Sciton

Diode Lasers at 810nm:

LightSheer by Coherent

Sonata by Alma (formerly Orion)

Alexandrite at 755nm:

Apogee by Cynosure

Gentlelase by Candela

Ruby at 694nm: Epilaser by Palomar

IPL(operating at about 600nm and up):

Harmony by Alma

MedLux by Palomar

Xeo by Altus

What areas of the body can have laser hair removal?
Any and all parts of the body can be treated (and have been treated) using lasers and IPL.
In women the most commonly treated areas are the upper lip, chin, bikini line, underarms, and legs.

Men most commonly request treatment of neck, shoulders, chest, and back. Even the ears and nose can be treated.

Many practitioners are cautious about treating eyebrows because of a theoretical potential for eye damage. Even with opaque goggles, some people report a sensation of light when treating near the eyes. This is likely of no significance, but most people prefer to be cautious around eyes until there is evidence of safety. In our office, we have successfully sculpted eyebrows using lasers. Most practitioners also have no worries about treating hair between the eyebrows.

What types of hair respond to laser hair removal?
The higher the contrast between the hair color and skin color the better.

The coarser the hair the easier it is to treat. Coarser hair responds better than fine hair to laser treatment, because there is more heat generated when the hair burns.

Fine "peach fuzz" (vellus) hair does not respond to laser treatment (no color to absorb the light). For permanent results, vellus hair is best treated by electrolysis.

Fine dark hair will burn when treated, but not enough heat will be produced to kill the hair follicle. It may be injured with each treatment, but the many treatments will be required to finally kill the follicle.

Laser treatment is ineffective on blonde and white hair, because it contains little or no melanin. Similarly, laser treatment of red hair hair is difficult, because this pigment reflects the laser light. (All hair removal lasers use light in the red to infrared range.)

What are the advantages of laser hair removal over other procedures?
Electrolysis requires the insertion of a needle into individual hair follicles followed by the application of a low intensity electrical current. While this can result in permanent hair removal, the process is tedious and requires numerous treatments, frequently over a period of years.
In contrast, laser treatments cover large areas in a matter of minutes. About six laser treatments over the course of a few months are all that is required to achieve long lasting hair reduction.

Waxing, shaving, tweezing, threading, and depilatory creams are all maintenance techniques with no lasting benefit. Laser treatment produces long-lasting hair reduction following only a few treatments.

Laser hair removal may seem expensive, but the long-term hair reduction achieved will actually give you significant savings in money and huge savings in time. Imagine never having to shave or wax again!

What are the risks of laser hair removal?
The laser hair removal procedure causes mild to moderate pain. This pain rarely persists following the treatment.

Mild redness is normal and usually lasts an hour or two. Rarely, it may persist for a few days.

The intense light of the laser can cause burning and blistering, but this is very rare. Blistering may lead to permanent scarring.

Pigment changes can occur. This can be increased pigmentation or decreased pigmentation in the treated area. Long wavelength lasers are very unlikely to produce any pigment changes. On the other hand, pigment changes are common with IPL, because intense pulsed light is designed to remove pigment such as age spots. Pigment changes are almost always temporary, lasting perhaps a few months. Increased pigmentation can be treated with creams. There is no good treatment for decreased pigmentation.

Occasionally people develop a light-induced rash (photodermatitis), which can be intensely itchy but goes away on its own in a few days. It can be treated with cortisone cream.Some people are prone to light rashes, and some medications can cause light rashes.

Your eyes can be injured by laser shots. You will be given glasses that filter out the wavelength of the device being used.These glasses will not protect you from a direct hit from a laser. Opaque goggles can be worn to give total protection. These goggles should be worn when you get facial areas treated.

How painful is laser hair removal?
There is no simple answer to this.
Pain is very subjective and varies greatly from person to person. Most people tolerate the procedure very well.

Some laser pulses feel like the snapping of an elastic band or a mild electric tingle or shock. Other laser pulses are not felt at all.

Most people who have experienced waxing and electrolysis prefer laser treatments.

Certain areas of the body are more sensitive than other areas. There is likely to be greater discomfort over bony areas such as the shin. The area just below the nose is very sensitive. In the underarms, there are large nerves that pass close to the surface that may be sensitive to treatment.

When treating coarse hair, more heat is generated (a coarse hair burning makes more heat than a fine hair), and this is more uncomfortable.

What can be done to minimize the discomfort of laser hair removal?
Shaving prior to treatment removes hair from the surface that would otherwise burn and add to the discomfort.
Shave the day before. Avoid shaving immediately prior to treatment, because shaving sensitizes the skin.

Some lasers have cooling tips that chill the skin to protect it and reduce discomfort. Others use cold liquid spray to cool the skin. Cooling gel packs can be used to reduce discomfort.

Many clinics use a cold air blower (Zimmer Cooler). This is probably the best method, because it cools before, during, and after each laser shot. The air coming out of a Zimmer cooler is cold: -30C. It can cause frostbite if it is left blowing on one area of skin.

Topical anesthetic creams can be used to numb the skin. Many people use these creams when treating the upper lip, bikini, and underarms. Treatment of other areas such as the legs is usually better tolerated.If you choose to use anesthetic cream, it needs to be applied 30-60 mintes prior to treatment and left in place until immediately before treatment.

It is perfectly reasonable to take analgesics such as Tylenol (acetaminophen), Advil (ibuprofen), or codeine prior to treatment. It is also perfectly reasonable to take tranquilizers such as Ativan or Xanax. Prescriptions can be provided by physicians (one advantage of being treated in a physician's clinic instead of a spa or salon). Very few people require any kind of oral medication.

Does laser hair removal increase my risk for skin cancer?
Absolutely not.
The wavelengths of light that produces skin cancer is in the ultraviolet range of the spectrum and beyond (into xrays and gamma rays).

Lasers for hair removal produce light at the opposite end of the spectrum in the red to infrared range. This light will not cause skin cancer.

All IPL devices have filters that block out the light in the ultraviolet range.

Will laser hair removal make my hair coarser?
No.
The goal of laser hair removal is to prevent the re-growth of hair. Hair follicles that are destroyed will not regenerate. Hair follicles that are only injured may continue to produce hair. In most cases, this hair is lighter in color and finer in texture.

Can laser hair removal achieve complete removal of all hair?
There is no system of hair removal that will ever achieve total elimination of hair. You will always have some hair.
Laser hair removal might destroy up to 50% of hair follicles in the first treatment. In the second treatment 50% of what remains might be destroyed. Again in the third treatment 50% of what remains might be destroyed, and so on. After about six treatments about 1-2% of hair follicles survive. At this point most people are very happy with the results.

The laser does not eliminate vellus hair (peach fuzz). Vellus hair can convert over time into terminal (coarse) hair. This conversion is a natural process of aging caused by hormone effects.

The goal of treatment is significant hair reduction.

Is laser hair removal really permanent?
Hair follicles that are killed by the laser will not regenerate (permanent).

Hair follicles that are only damaged may continue to produce hair. Some follicles are not damaged at all.

Don't forget about the conversion of peach fuzz to real hair.Fine "peach fuzz" (vellus hair) can convert under the influence of hormones and aging to new coarse hair (terminal hair).

This is of particular importance in women's faces. In men, facial hair converts from peach fuzz to coarse hair over a period of several years following puberty. In women this process is lifelong. Therefore, when women undergo laser hair removal, only the coarse hair is eliminated. This leaves peach fuzz that will convert to coarse hair sooner or later.

The laser will not stimulate this conversion of vellus to terminal hair. This is a natural process driven by hormones.

The goal of treatment is long-term hair reduction.

How many laser hair removal treatments will be required?
With each treatment, only a certain percentage of hair follicles are destroyed.
If 50% of hair follicles are destroyed with the first treatment and 50% of the remaining hair follicles are destroyed with the next treatment and so on, after four treatments approximately 90% hair reduction would be achieved. However, 50% reduction with each treatment cannot necessarily be achieved. The success of each treatment depends on many factors including hair color (darker is easier to treat), hair texture (finer is harder to treat), skin color (darker is harder to treat), and hormone status (excess testosterone stimulates conversion of vellus hair to terminal hair).

Most people will be satisfied with 4-6 treatments (coarse dark hair such as the bikini line), but some will need 10 or more (fine hair such as the upper lip).

What I can expect following laser hair removal?
Immediately following treatment you may experience some redness and slight swelling of the skin.

There may also be some very mild lingering discomfort. In almost all cases these effects are gone in the first hour. Rarely, they last for a day or two.

You can return to your daily activities immediately following laser hair removal.

Immediately following treatment, you will be able to wipe away some of the hair that has been destroyed. However, you are not likely to see an appreciable reduction in the amount of hair immediately. Hair reduction will only become evident over the next few weeks. For a week or two following treatment, hair follicles that have actually been destroyed may appear to have growing hair. In fact, this is simply hair that is being expelled from the damaged follicles. These hairs are easily pulled from the skin. Undamaged hair is still firmly attached and cannot easily be plucked.

Should I avoid tanning prior to laser hair removal?
Yes and no.

It depends on the laser.

For long wavelength lasers such as the NdYAG, tanned skin is of little importance.

For short wavelength lasers (less than 800 nm) and IPL, tanned skin can be dangerous to treat. Burning and pigmentation changes can occur.

What skin colors can be safely treated with laser hair removal?
Long wavelength lasers (greater than 800 nm), such as the NdYAG, are safe and effective for people of all colors.
However, because dark skin absorbs more laser light, treatment energy might need to be reduced to keep the skin safe. Lower energy means each individual treatment is a bit less effective, so more treatments may be required.

Short wavelength lasers and IPL are safe for use on light skin.

What hair colors can be treated with laser hair removal?
Dark hair is easy to treat.

Blonde and white hair contains no melanin. It cannot be treated using any type of light.

Red hair responds poorly to lasers and intense pulsed light, because these devices all use red to infrared light, and this light is reflected by red hair.

Can I shave prior to and between laser hair removal treatments?
Absolutely!
In fact, you should shave prior to treatments. The laser is targeting the hair root, which is unaffected by shaving (and depilatory creams). Shaving removes hair above the surface that can absorb the laser light and reduce the amount of energy delivered to the roots. The laser will burn surface hair, which can add discomfort to the treatment, not to mention the distasteful odor of burned hair!

Shaving prior to treatment also allows you to show the practitioner exactly the area you want treated, which is important for bikini lines and men’s necks and backs.

Unlike waxing, plucking, threading etc. you don't need hair above the surface for the treatment to work, so you can shave between treatments (until you never need to shave again!).

Shaving will not make your hair coarser, denser or faster growing! This is probably the most deeply entrenched popular misconception in the female psyche. It has been thoroughly disproved by dermatology studies!

Can I pluck or wax before laser hair removal treatments?
No.
These hair removal techniques remove the hair root that is the target for the laser. If there is no hair in the follicle, no energy is absorbed, and the hair follicle is left undamaged. You must wait about six weeks after using one of these techniques to allow regrowth of target hairs for the laser.

Can I dye or bleach my hair before or between laser hair removal treatments?
Bleaching and dyeing do not affect the roots.
Therefore, the melanin in the hair follicle is still present to absorb the laser light. Bleaching dark hair will not reduce the efficiency of the laser. Likewise, dyeing blonde gray or white will not increase the efficiency of the laser.

How long do laser hair removal treatments take?
Treatment time varies according to the area being covered and the device being used.
The upper lip is a very small area that can be covered in a few minutes. For most lasers, it takes about one hour to do both lower legs. A man's back will require about 1 hour.

IPL devices use a much larger tip. One shot is about the same as 8-10 shots from most lasers.

Some lasers use "scanners". This is a device that fires several laser pulses in rapid succession and aims the shots to "scan" over a large area. This speeds up treatment.

At what intervals are laser hair removal treatments repeated?
You should allow an interval of 6 to 12 weeks between laser treatments on the same area.

Hair follicles have a life-cycle with three phases. In Phase 1 there is actively growing hair in the follicle. In Phase 2 the hair stops growing and begins to loosen. In Phase 3 the hair falls out. The cycle is then repeated. Laser treatment is most effective during the active growth in Phase 1. It is ineffective in Phase 3 when there is no hair in the follicle.

Laser hair removal treatments are spaced at six week intervals to make sure that hair follicles that are in the resting phase during one treatment have returned to active growth in a following sessions.There is no advantage to waiting longer than 12 weeks.

What should I do to prepare for laser hair removal treatment?
Avoid waxing, plucking, and electrolysis for at least six weeks prior to treatment.

Avoid tanning.

Shave the area you want treated. This should be done the day prior to treatment. Shaving the day prior to treatment allows the skin time to recover from the irritation of shaving and reduces the discomfort of the procedure. Allowing one day of growth before treatment helps the practitioner to see the area to be treated.

Do not apply makeup or deodorants. These can absorb the energy of the laser light, reducing the efficiency of treatment and increasing the risk of burning.

Remove reflective jewelry in the area to be treated. Directly reflected laser light can cause serious eye damage to the laser technician.

Wear clothing that will allow easy access to the area to be treated (eg. tank top or sleeveless shirt for underarms; skirt, track pants, or loose pants for legs). For bikini line, wear an old swimsuit or under pants. The laser is easily capable of burning natural fibers and melting synthetic material.

What are my restrictions after laser hair removal treatments?
Other than avoidance of the sun, there aren't any restrictions.

You can return to work or other daily activities immediately.

You should avoid sunlight and tanning beds for at least three days before and after treatment forlong wavelength lasers and for two weeks for short wavelength lasers or intense pulsed light. This allows the skin time to settle and reduces the risk of developing excess pigment. A broad spectrum sunscreen should be employed with minimum SPF 15. SPF 30 to 60 is preferred.

You can shave between treatments, but avoid plucking and waxing.

Can my children have laser hair removal?
Yes, with a few cautions.

It takes a few years following puberty for all the hair in the area to convert from peach fuzz to coarse hair. If laser hair removal is done before this process is complete, further conversion of hair will occur, and treatments will have to be repeated in a few years.

Another factor is the pain tolerance of children. It might be quite unfair to subject your child to this uncomfortable experience.

Your child has to be quite motivated to undergo laser hair removal. Let your child decide.

In our office, we will not treat children under the age of 12, unless there is a medical reason (for example, treatment of a hairy nevus).



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