Many Hairs, Three Phases of the Growth Cycle

  • Posted on: Jun 30 2021
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At Spa Vitoria, laser hair removal is one of our more popular treatments. And why not? Who enjoys shaving, waxing, plucking, and applying harsh depilatory creams in the quest for the ultimate bikini line or to remove those unwanted sideburns? Patients sometimes wonder why it takes a number of sessions to get rid of their unwanted hair. Can’t you just zap them all at once, they ask? 

The problem, we explain, lies in the hair growth cycle, along with the fact that we’re thoroughly mammalian, complete with around five million hairs on our bodies. 

Human hair has three phases in its growth cycle, and laser energy is really only effective when the hair is in one of those phases. The trick is to catch as many hairs at that time as possible. 

Three cycles 

Each of our hairs operates like an independent contractor, five million of them. Each hair is doing its own thing. Sure, certain areas tend to spend more time growing, such as the beard area on the male face. But each hair is moving through the grow cycle on its own. 

That cycle includes the anagen (growth) cycle, the catagen (transitional phase between growth and rest), and the telogen phase (rest). The catagen and telogen phases involve stopping nourishment to the hair, shedding it, and restarting a new hair shaft. When the hair is in either of these phases of the growth cycle laser energy has no effect on it; the hairs are already on their way out. And the laser energy can’t get into the follicle to damage it. 

For our Spa Vitoria lasers to be most effective on an individual hair, it needs to be actively anchored in the hair follicle. This happens only in the anagen phase. The hair is receiving nourishment through the hair follicle and it is still growing. The body isn’t ready to shed this hair yet. When we apply pulses of laser energy to this hair, the melanin in the hair shaft absorbs the light and it converts to heat. The heat travels down the hair shaft into the follicle. The heat damages or destroys the hair follicle, and this precludes it from growing hair in the future. 

You can see the challenge. Five million hairs, only some of them in the anagen phase at any one time. That’s why it takes multiple laser hair removal sessions to build the level of permanent hair reduction. The goal is to catch more and more hair in the growth phase. 

This is why the FDA approval for lasers and hair removal is for what it deems “permanent hair reduction.” You notice that it doesn’t say complete removal. Most patients can achieve up to about a 90 percent reduction in their treatment areas. 

Now that we’re finally getting past COVID, this is a great time to get started on your laser hair removal quest at Saltz/Spa Vitoria. Give us a call at our Salt Lake office, (801) 274-9500, or our Park City office, (435) 655-6612, to make an appointment.

Posted in: Blog, Laser Hair Removal

Saltz Plastic Surgery &
Saltz Spa Vitoria

Salt Lake City
5445 S Highland Dr
Salt Lake City, UT 84117


Park City
1441 Ute Blvd. Suite 140
Park City, UT 84098


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Salt Lake City 435.655.6612 | Park City 801.274.9500