Everything You Need to Know About Laser Hair Removal

Laser hair removal had been on my “someday” list ever since a kid in my A.P. Chemistry class commented on my mustache. (I'm partly Southern Italian with robust hair follicles—what can I say?) Obviously the kid was a jerk and there's nothing wrong with body hair, but the fact remained that as I got older, I still wanted it gone. When I finally got around to it, though, I had a lot of questions. Is laser hair removal painful? How many sessions was I in for? Was my skin—always tans, never burns, year-round medium—too dark for laser hair removal? 

The process is more complicated than other in-office procedures, which is why it requires a bit more explanation than, say, your average chemical peel. Here's what you need to know—and everything I certainly wish I'd known—before booking an appointment.

How does laser hair removal work?

Think of laser hair removal as a video game, says Ellen Marmur, M.D., a dermatologist at Marmur Medical in New York City. The laser seeks out pigment in your skin, which is typically found in the base of your hair follicle. Once the laser locates the hair follicle root, which houses your hair stem cells, “the laser then converts from light energy to heat and basically explodes it,” she says. The hair root dies, and the hair falls out.

Because the laser works by seeking out pigment, it's best to time it right—basically, you want to limit the amount of other pigment in your skin, like that from sun exposure. “Patients are less likely to be tanned in winter and spring,” says David Kim, M.D., the dermatologist at Union Square Laser Dermatology in New York City who zapped my upper lip. “If you're tanned, the energy from the laser can be absorbed by your skin in addition to the hair follicles—and cause burns or blisters and leave a disfiguring scar.”

If your skin type is a 3 or higher on the Fitzpatrick scale (which takes into account both skin tone and ethnicity), you may need a special laser. Since I'm a 4, Kim used Candela's GentleYag, which is an ND:Yag laser. “It uses 1064-nanometer wavelength, which is much safer and very effective for patients with darker skin type,” he says. “In contrast, I use GentleLase for patients with lighter skin type, which uses 755-nanometer wavelength.” That shorter wavelength is more powerful, and better suited for skin with less pigment. (For more on this, check out our guide to laser hair removal for dark skin.)

Either way, you'll definitely need multiple sessions, though it depends on a huge variety of factors, including “skin tone, the type of hair and body location, the type of laser, the settings and power that you're using with the laser, and even the time of year,” says Marmur. But expect to need at least three sessions.

How to prepare for laser hair removal

You're going to need your follicle roots intact for the laser to do its job, so avoid waxing, tweezing, threading, or anything else that removes hair at the root before your appointment. Then “shave the areas one to two days prior to the treatment, but not the day of the treatment,” says Kim.

Also, consider the beach off-limits. Two weeks before your appointment, avoid the sun, especially if you're getting hair lasered on sun-exposed areas like your face, neck, chest, back, arms, and legs. No matter your natural skin tone, it'll put you at risk for side effects.

When you arrive at the office, expect to do a test spot, especially if your skin is very fair or naturally medium to dark. “Sometimes we'll do a test spot in a hidden area, like the underarm,” says Marmur. “Then we can see if you're the kind of person who gets really, really red afterward, for example.” Any reactions will be immediate, so the technician can address it on the spot.

What are laser hair removal side effects?

Let's start by clarifying: There are expected side effects, and then there are unwanted side effects of laser hair removal. We'll cover the expected stuff first. A little pinkness and swelling is normal, as are tiny goose-bump-like bumps; those are actually from the swelling of the injured follicles beneath the skin. You also may notice “little black specks that come out of your skin,” says Marmur. “People often misconstrue that as new hair growth, but it's not—it's dead hair shedding.” That's a sign that the laser hair removal worked.

The unwanted side effects include blisters, scabbing, hyperpigmentation, and hypopigmentation. Of some comfort: Pigmentation issues aren't always permanent. “If you get it, let your doctor know right away and use a little cortisone 1% cream on the area,” says Marmur. Keep it out of the sun and heat, and apply a cool compress ASAP.

If you're predisposed to hyperpigmentation, your dermatologist may even make a preemptive strike. “For patients with darker skin types, we apply over-the-counter hydrocortisone 1% cream in the office to minimize inflammation and the risk of darkening of skin, or post-inflammatory hyperpigmentation," says Kim. "We recommend applying the cream twice daily to the affected areas for three to five days.”

Is laser hair removal painful?

It largely varies, since the lasers themselves have gotten better over the years. “I've had patients who were able to tolerate the treatment without any numbing, and patients who experienced some pain even with topical anesthesia,” says Kim. (I, a baby, prefer to spend an hour with numbing cream and have never felt a thing.)

Marmur compares the laser beam to a zinging feeling, similar to a needle prick. She's a fan of contact cooling systems, as they blunt the heat created as the laser beam (which is light energy) converts into heat. Plus, they offer enough cooling to minimize any damage caused to surrounding skin, reducing the risk of hyperpigmentation.

Certain pain-reducing methods, like suctions and contact cooling, are often built into the lasers. “There is a new laser by Lumenis called Splendor that is very effective and significantly more comfortable than other existing lasers, and I have had great success with it,” says Kim. “Because this laser is much more comfortable, I have been able to treat almost all patients without any topical numbing cream which significantly reduces the waiting time for the patients as well.”

Aftercare for laser hair removal

Since laser hair removal heats up your skin as it blasts your hair follicles, it's important to cool it back down afterward to avoid side effects like redness. “We often give people cold gauze in Ziploc bags,” says Marmur. “If you're getting in a car, put on the air conditioning and stay in a cool place for a bit, or take a cool shower afterward.”

Marmur sends her patients home with a cooling serum, the Marmur Metamorphosis MMRevive Serum. You could also try Avéne Cicalfate Restorative Protective Cream, which soothes with a combination of barrier-repairing ingredients and probiotics.

Avoiding sun exposure and wearing sunscreen is also a must, as sunlight can kick-start hyperpigmentation. Kim recommends wearing a minimum of SPF 30. Got another session coming up? “Patients should not wax, pluck, or thread the treated areas in between treatments, because it's essential for the hair follicles to be intact in order for the treatments to be effective at the next session," he says.

How long does laser hair removal last?

If we're being technical, laser hair removal is something of a misnomer. It's more like laser hair reduction, says Marmur. That's because you have two types of hair: vellus hairs, which are fine baby hairs, and terminal hairs, which are more coarse. “The vellus baby hairs get affected by hormones and convert to terminal hairs throughout your life,” she says. 

So you may do laser hair removal at 18, but by 30, you might have new growth coming in. It's just nature doing its thing. That being said, once a hair follicle root is dead, it's dead forever.

Is laser hair removal safe?

Always make sure you're going to a board-certified dermatologist or reputable practitioner—this isn't a procedure you want to cut corners on just because you found a good discount online. And don't be afraid to ask for a consultation ahead of an appointment to discuss the procedure. As for during your appointment, you'll want to make sure both you and your practitioner have safety goggles on while the laser is in process. 

At-home laser hair removal devices also exist, but they're generally less effective (meaning it will take much longer to see results), and there’s more room for error as the beam is less specific. This is why experts generally suggest going in-office for the procedure.

How much does laser hair removal cost?

Laser hair removal costs an average of $285 for one session, according to the latest stats from the American Society of Plastic Surgeons, but some treatments can run up to $1,500 per session. That's because the cost varies widely according to a number of factors, such as the size of the area you're treating, the provider's expertise, and where you're located. Just remember: Any treatment that seems too affordable to be true often is.