In this article:
How does laser hair removal work?
What is the best laser for hair removal?
What to expect with laser hair removal
How many laser sessions are required to remove hair?
Do laser hair removal results last?
Laser hair removal side effects
Is laser hair removal the right choice for you?
While removing unwanted body hair at home by shaving, waxing, or plucking isn’t all that difficult, it’s a time-consuming chore—and can also cause ingrown hairs and excess pigmentation (1).
The appeal of getting rid of that hair—possibly for good—is strong; who doesn’t want that extra time back? Since its approval back in the mid-90s, laser hair removal has grown steadily in popularity. Let’s find out if it’s the correct hair removal solution for you.
How does laser hair removal work?
Laser hair removal is a process that relies on light to reduce, not eliminate, hair production. It’s important to note laser hair removal is U.S. Food and Drug Administration (FDA) approved to promote hair reduction, not permanent elimination. The only permanent method of hair removal recognised by the FDA is electrolysis, which isn’t laser-based.
While there are several different types of laser hair removal processes, they work similarly: A medical professional uses an intense, pulsating beam of light (a laser) that passes through skin and is attracted to dark pigment (eumelanin) in the hair follicle during the anagen hair phase (the phase associated with hair growth) (2). The laser focuses intense heat on the hair follicle, causing damage, which eliminates or at least slows recurring hair growth; this process is called selective phytothermolysis (3). After lasering, the “dead” hair inside the follicle will begin to fall out within 7-14 days. This procedure is quite safe and designed to not damage the surrounding skin.
Laser works best on terminal hair (coarse, thick hair that we see on the scalp, underarms and pubic area) versus vellus hair (peach fuzz or thin hairs) (4). When laser hair removal is done on vellus hair, it can turn into terminal hair (who wants that when trying to remove hair?).
What is the best laser for hair removal?
As far as the types of lasers used, ruby, alexandrite, diode and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers are all U.S. FDA approved options for laser hair removal. Let’s jump into their benefits and differences:
- Ruby 694 nm lasers are the most effective, but they typically are only safe for Fitzpatrick skin types 1-3 (pale-to-medium skin tones).
- Alexandrite 755 nm lasers are the second-best choice but again are only safe for pale-to-medium skin tones.
- Diode 810 nm lasers are the third best laser option and the range of skin types it’s able to treat is slightly less limited, as they’re able to safely treat Fitzpatrick skin types 1-4.
- ND Yag 1064 nm lasers are the least effective option, but they can be used on all skin types. They are essentially the only laser option for Fitzpatrick skin types 5 and 6 (dark skin tones that rarely burn). This wavelength is longer than the others to prevent burning and is typically reserved for lighter skin tones if they have recent sun damage.
You’ve also probably heard of intense pulsed light hair removal, or IPL. Though it does use light to remove hair, it’s not technically a laser because it uses a range of wavelengths instead of a focused wavelength. Despite this difference, it works in much the same way as laser hair removal—that is, it heats the follicle, although with less intensity and at a shallower depth. IPL is almost as effective as laser and is less painful but requires more treatments. IPL can increase the risk of burning for darker skin tones and is typically not recommended on this range of skin tones.
What to expect with laser hair removal
Session cadence, results and side effects are important things to consider when it comes to laser hair removal and can directly impact the chances of hair regrowing. Let’s get into how!
How many laser sessions are required to remove hair?
Laser hair removal is not a “one and done” process to achieve desired results. Board-certified dermatologist Dr. Debra Jaliman recommends laser hair removal, but notes “it does take multiple sessions.” This is because not every hair in a treatment area is in the same hair growth stage at the same time—they may be in the resting or shedding phase—and laser hair removal only works on hair in the anagen phase.
For the face, about 6-10 sessions are needed with appointments spaced out to every 4 to 6 weeks (those with hormone imbalance-related facial hair may require more). For most of the body, the same number of sessions (6-10) is typically needed, however they’re spaced out every 6-8 weeks due to the body’s slower hair growth cycle.
Do laser hair removal results last?
The answer is: sometimes! Many people who get laser hair removal are happy with the results; however, it’s important to note that this service doesn’t always result in permanent hair removal. In many cases, it only lessens hair growth, which means you won’t need sessions, or to shave, as frequently.
Usually, depending on skin colour, hair colour and hair thickness, results should become apparent after 2-6 sessions. If hair regrowth occurs, it’s often lighter in colour and finer overall. Still, many people find it worth the time and money—you might be one of them!
In order to generate the best possible results, it’s critical to do research before you make an appointment. Make sure the doctor you choose is board-certified and check reviews online to see patients’ feedback. Once you book an appointment, do not wax, thread, sugar or tweeze any hair you want removed because it needs to be within the follicle for lasering to work (shaving is ok, it leaves the hair within the follicle).
Laser hair removal side effects
Side effects generally range from mild skin irritation and some swelling with redness, (which usually disappears in a few hours) to lightening or darkening of the skin around the follicle (which usually goes away in a few weeks). Don’t worry, these side effects are often a good thing. They mean the procedure has reached a perfect clinical endpoint.
When treating thicker facial hair, some may experience breakouts that usually subside without treatment.
Some rare, but serious, adverse reactions include burns, hypopigmentation, hyperpigmentation, infection and permanent scarring.
Is laser hair removal the right choice for you?
Laser hair removal isn’t a one-size-fits-all treatment. Its specific technology works best on a certain range of skin tones, hair colours and hair consistencies. Outside of this, there are other lifestyle factors that may make impact your ability to undergo this treatment.
Who is laser hair removal best suited for?
Laser hair removal is best suited for those with lighter skin tones and dark hair. This is because the laser targets the pigment (melanin) in hair, not the hair itself. The contrast between dark hair and light skin allows the laser to effectively target the pigment in hair over the pigment in skin; meaning the laser only damages the hair and follicle, not the skin.
Who is laser hair removal not suitable for?
Laser hair removal isn’t suited for those with both a darker skin tone and dark hair. The reduced contrast between the skin and hair means the laser might target the pigment in the skin instead of that in the hair, resulting in a higher risk for skin damage. However, modern lasers have improved upon this ability.
It’s also best to skip out on laser hair removal if you have light hair because of the lack of pigment (which is what lasers target, as we mentioned above).
You should also second-guess laser hair removal if...
- You’ve used topical actives, like retinoids, AHAs (alpha hydroxy acids) and BHA (beta hydroxy acid) and topical antibiotics within the past 2 weeks.
- You’re pregnant.
- Areas with hair you want removed have irregular pigmented or raised moles, warts or fleshy growths.
- You’re taking medication, supplements or herbs (such as St. John’s Wort) that can cause photosensitisation and can contribute to burning (discuss with your practitioner).
- You have epilepsy or seizures and know intense light to be a trigger (discuss with your practitioner).
- You have herpes, since laser hair removal may stimulate an outbreak.
- You’re prone to keloid scarring.
- You’re undergoing chemotherapy. It's recommended to wait 1 year past your last session to receive laser hair removal.
- You have recently experienced sun exposure or used a self-tanner, in which case wait 4 weeks until your appointment.
- You’re receiving resurfacing treatments like chemical peels, in which case wait 2-4 weeks before your laser appointment.
- You have psoriasis- or eczema-prone skin because it may cause a flare up.
- You take the anti-acne medication Accutane.
- You have tattoos in the areas you want lasered. Lasering tattoos can cause burns and blisters.
Overall, you should reach out to a doctor to make sure laser hair treatment is best for you.
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References for this information:
- International Journal of Cosmetic Science, October 2020, pages 436-443
- American Journal of Clinical Dermatology, April 2002, pages 107-115
- Journal of Cosmetic and Laser Therapy, April 2019, pages 316-322
- Dermatologic Therapy, Jan/Feb 2011, pages 94-107