by Alissa Mariello, LE, LLP // October 2025
As a licensed laser practitioner in North Carolina and someone who has received laser hair removal on multiple body areas, I’ve seen firsthand the life-changing results of laser hair removal. If you’ve ever gone to the beach and worried if you have hair sticking out of your bikini bottoms, or wondered what women will think when they see you in your swimsuit with a hairy back; if you’ve ever raised your arm up joyously only to snap it back down as you question the last time you shaved your underarms – you know what I’m talking about.
In this way, laser hair removal is a form of freedom. You can go out with confidence, wear the bikini without worry, and spontaneously accept a last-minute invitation. You don’t have to worry if you missed a spot, if she’s going to wrinkle her nose when she sees all your chest hair, or if a warm caress of the chin is going to give away those new chin hairs you never used to have.
How Laser Hair Removal Works
The pursuit of permanent hair removal has a long history, but effective, long-term reduction is a modern marvel. The concept of using light energy for hair removal began in the 1960s, but the true breakthrough came in the mid-1990s when researchers developed the principle of selective photothermolysis.
This scientific advancement led to the first FDA-cleared lasers for public use in the late 1990s, paving the way for the sophisticated, safer, and more inclusive technology we use today.
It works by using a concentrated beam of light that targets the melanin, or dark pigment, in the root of the hair, which converts that light into heat that disconnects the hair to its blood supply – a major factor in hair growth – and destroys the cells that feed hair growth. Because the laser is a concentrated form of energy targeting pigmented colors at precise skin depths, the hair can be destroyed at the root, where growth occurs, and the surrounding tissue and cells remain unharmed.
As you complete multiple sessions (most people need 6-12 sessions to achieve an 85-95% permanent hair reduction), the hair becomes finer, lighter, and more sparse, until finally almost all of your hair is permanently gone, and what’s left is fine, light, and grows slowly. There is sometimes confusion about what kind of results you can expect from laser hair removal. The FDA cleared it in the 1990s as “permanent hair reduction” because it often doesn’t get every single hair, and occasionally needs a couple touchups every few years. That being said, most people achieve significant, life-changing permanant hair reduction over 6-12 treatment sessions. This time factor is the reason why many spas don’t offer single sessions but instead offer packages. They know you can’t achieve the results you’re looking for in just one visit; depending on the laser used, the settings chosen, and the practitioner’s knowledge, it most often takes at least 6 sessions.
The Importance of Timing
In terms of time to achieve the best results, it varies by body area because of the growth cycle of hair. Hair growth goes through three main phases: anagen (growth phase), catagen (transition phase), and telegon (resting/shedding phase). Laser hair removal works best on actively growing hairs, and each body area experiences different lengths of time for each phase. Hair growth on the face tends to have shorter cycle times, and as a result, sessions should be spread 4-6 weeks apart – any less or more time will decrease the number of hairs in the active growting stage and therefore achieve slower results. Body hair growth tends to have longer cycle times, so treatment on these areas should be 6-8 weeks apart.
Laser Hair Removal Works on all Skin Tones
….If you have the right laser machine. There are two wavelengths best suited for permanent hair reduction that can only be achieved with a Class IV laser: the Alexandrite wavelength (755 nm) and the NG: YAG wavelength (1064 nm). Each wavelength has been studied and determined to be the precise wavelength needed to achieve permanent hair reduction for certain skin tones. The Alexandrite works best for fair to medium skin (Fitzpatrick 1-3), and the NG: YAG works best for darker skin tones (Fitzpatrick 4-6). The Alexandrite will not work on darker skin tones, as it can cause burning, so if you have a darker skin tone, make sure your practitioner has a laser that can also utilize NG: YAG, which is the only safe wavelength for those with darker skin. The Alexandrite produces a stronger energy level and works very well for those with more contrast between their hair color and skin color — fair to medium skin color with darker hair tends to work very well with the Alexandrite wavelength. IPL is another form of permanent hair reduction, but be weary if your spa uses one. IPLs utilize a separate technology that does not produce a concentrated light, but rather a scattered light that is not as powerful. It can still work for permanent hair reduction, but it often takes significanly more sessions and longer time-frames, and should therefore be priced appropriately.
Key Takeaways
Laser hair removal was a breakthrough in the 1990s when selective photothermolysis was discovered and applied to permanent hair reduction.
Here’s how it works:
- Concentrated beam of light targets pigmented root of hair, destroying growth ability while leaving surrounding tissue unharmed
- Requires multiple sessions, usually 6-12, to achieve 85-95% permanent hair reduction, with hairs becoming lighter, finer, and slower-growing each time
- Facial hair sessions should be spread about 4-6 weeks apart for best results, and body hair sessions should be spread about 6-8 weeks apart for best results.
- IPLs (both in spas and at-home devices) have much weaker, more scattered energy and often take significantly more time to achieve good results. Be ware that at-home devices are often not strong enough to produce good results and can prompt more growth as a result, instead of less.
