Advertisements and “buzz” about laser-assisted hair removal are everywhere. We’re promised permanent, painless, risk-free hair removal by salons, “laser centers”, and cosmeticians. But what is the truth about laser hair removal? How does it work and will it work? Is it painful? Who is right for laser hair removal and who isn’t? Let’s dispel some of the myths surrounding laser hair removal, get beyond the hype and explain the technique.
The first step to understanding how laser technology removes unwanted hair is to understand how hair grows. Your hair follicle is located under the skin, approximately 1 to 3 millimeters deep, depending on the site. It has three phases: growing (anagen), resting (catagen), and shedding (telogen). At any given moment, most hairs are in anagen, a time when they are susceptible to destruction. Different parts of your skin have differing proportions of hairs in anagen, catagen, and telogen, and this affects how many laser treatments you will need to eliminate unwanted hair. This explains why, after a successful laser treatment, all hairs will appear to shed, but a proportion of hair re-grows within a month or so. The effectiveness of your initial treatment will depend largely on the body site treated.
Next, we have to understand how lasers work. Lasers send out beams of light with a few special characteristics: they are of a single wavelength (a pure color), coherent (all waves move together), and focused. Their color determines what chromophore (light-absorbing molecule) will absorb the laser energy and be destroyed. For example, the Carbon Dioxide laser light, used for facial resurfacing, is absorbed by water. Since all human cells contain water, this laser is a non-specific destroyer of cells. Hair-removal lasers, on the other hand, are absorbed by melanin, the pigment in skin and hair. This laser works better when there is less melanin in your skin, and more in your hair. It is for this reason that laser hair removal is always most efficient for white-skinned, black haired people and least efficient for dark-skinned, light haired people. Even a tan will make the laser work less efficiently.
The laser beam passes through your skin, travels down about three mm, and ‘explodes’ the melanin-containing hair bulb. Lasers differ in their efficiency depending on how well they get their laser light through your skin and into the deeper tissue, how well they are absorbed by your hair bulb, and how little damage they do to the overlying skin. Your skin is protected from burning during treatment by keeping it cool several different ways: refrigerated laser probe tip, a cold spray or a pre-cooled gel. Multiple treatments (usually three) are needed to capture the majority of the hair follicles in their growing stage. It’s not as bad as it sounds.
There are also non-laser devices for hair removal which utilize flashlamp technology. This is essentially a very bright light, filtered to exclude some wavelengths but results are generally inferior to laser. One advantage of these devices for salon operators is that in many states they can be operated by a technician rather than a physician. Electrolysis is another hair removal procedure.
Who Benefits from Laser Hair Removal?
Anyone with relatively light skin (type IV or “mocha” or lighter), and dark hair (not blonde or red) can potentially benefit from this technique. Many manufacturers promote their devices as suitable for even patients with dark skin or blonde hair, but these claims are often exaggerated.
Some new lasers claim to work on dark black skin. This is only partially true, and temporary hair reduction, rather than permanent hair reduction is generally the rule. If you’re dark skinned, you may get transient (rarely permanent, but annoying nonetheless) increased or decreased pigmentation in treated areas.
While any area of your body can benefit from laser hair removal, certain areas — like your penis, eyebrows or anal area — are tricky to treat. Topical or injected anesthesia may make hair removal treatments more comfortable. Better pain control is another reason to be treated by a physician.
Who should not be treated?
There are risks to laser hair removal. These include pigment increases or decreases in the skin, but are generally rare — provided the laser and its settings are properly chosen. Like any other procedure, proper technique and supervision is essential, and anyone who chooses to be treated without physician supervision runs substantial risk of adverse effects.
If you have a history of Herpes simplex virus (cold sores, genital Herpes)in the area to be treated, take your herpes medication before and after laser hair removal.
Proper eye shielding is essential.
Tell your physician if you have a history of ingrown hairs before beginning any laser hair removal.
Laser treatments can be uncomfortable, even painful, especially in areas where the laser light is highly absorbed. Discomfort is most common in people with thick, dark hair, especially where the hair is dense.
Lasers can provide the opportunity for you to achieve permanent hair reduction quickly and with relatively little discomfort. The fact that lasers can successfully treat a large area at a time, and do not involve physical penetration of the skin by needles, make them a better choice than electrolysis. Electrolysis of the entire back can take years of sessions. As with any cosmetic procedure, realistic expectations are essential. Permanent hair reduction can be achieved in the ideal, light-skinned and dark-haired patient, with chances of success decreasing for those with less optimal skin- and hair-types. It is also important to remember that adults generally become hairier as they age, beginning in adolescence and peaking at around age 55. (Do you have hair growing out of your ears yet?) A 23 year old man may get true permanent hair removal for the follicles he has at that age, but new follicles will likely appear in the future, requiring re-treatment.
Overall, lasers offer the opportunity for rapid, efficient hair removal over large areas, but they work much better in some people than others. Get advice from an experienced physician you trust for optimal evaluation and devise a treatment plan most likely to succeed.
Points to Note
- The lighter your skin and the darker your hair, the more successful your laser hair removal will be.
- Tanning cuts down on laser efficiency.
- Multiple treatments are often necessary, depending on the area treated because hairs must be growing actively at the time of the treatment.
- Tell your doctor if you have a history of abnormal scarring, a tendency to form dark or light spots after injury, a history of cold sores or herpes infection.
- Realistic expectations are key. Be aware that new hair follicles may appear later, and that retreatment may be necessary.
- Laser hair removal is safe in people with HIV, but let you’re doctor know so that precautions can be taken to prevent infection
By Jeffrey S. Roth, M.D., Ph.D.