By Dr Garry Cussell, Rejuvenation Clinics of Australia
Laser hair reduction is one of the more straightforward professional treatments to explain, and also one of the most commonly misunderstood, largely because of how it gets marketed.
The terminology itself can be confusing. Can laser permanently stop a hair follicle from producing hair? Yes, it can. Does that mean we can promise permanent removal of every hair in a treatment area? No.
I want to explain that distinction, along with how the treatment actually works, so you have a realistic understanding of what to expect before you start.
How laser hair reduction works
Laser hair reduction works by targeting melanin, the pigment within the hair, with a specific wavelength of light. That energy is absorbed by the pigment and converted into heat, which is transferred to structures within the hair follicle.
When sufficient energy reaches the appropriate structures within the follicle, the resulting thermal effect can damage the follicle so that it is no longer capable of producing hair.
This is an important point because effective laser hair treatment isn’t simply about passing a laser over the skin. The technology being used, wavelength, treatment parameters, skin type, hair characteristics and experience of the person performing the treatment all matter.
The objective isn’t simply to use more energy. It’s to deliver the right energy, using appropriate treatment parameters, to sufficiently damage the target follicle while protecting the surrounding skin.
Because laser relies on melanin as its target, treatment generally works best when there is sufficient pigment within the hair for the laser to target. Very light, grey or white hair generally responds far less effectively because there is little melanin available to absorb the laser energy.
Why it takes a course of sessions, not one
Hair grows in cycles, and at any given time only a portion of the hairs in a treatment area are in the active growth phase when they are most responsive to laser treatment.
Hair in other stages of the growth cycle will not necessarily respond in the same way at that particular treatment session.
This is why laser hair reduction is delivered as a course of sessions spaced over time rather than as a single treatment. Each session gives us an opportunity to target another proportion of hairs as they move through their growth cycles.
Over a properly delivered course, more follicles can be effectively treated, progressively reducing the number and density of hairs growing in the area.
Why we call it hair reduction
This is where the terminology is worth understanding.
Laser treatment can permanently damage successfully treated hair follicles so that they no longer produce hair. But that is different from guaranteeing that every follicle within a treatment area will be permanently eliminated.
Not every hair is at the same stage of its growth cycle at the same time, and individual follicles don’t necessarily respond identically. Hair colour, skin type, treatment parameters, treatment area and hormonal influences can all affect the eventual result.
For that reason, the more accurate way to describe the overall outcome is long-term or permanent hair reduction – a lasting decrease in the number and density of hairs that regrow – rather than a promise of complete permanent hair removal.
A properly delivered course can produce a significant and lasting reduction in hair growth. Some clients may still experience some regrowth over time or choose to have occasional maintenance treatments.
Does the type of laser matter?
Yes. Several laser technologies are used for hair reduction, and they aren’t interchangeable.
I would rather explain the differences by how they work than tell you that one type of laser is universally “best”, because suitability depends on the individual being treated.
Diode lasers are commonly used for hair reduction across a range of skin types and hair characteristics.
Nd:YAG lasers use a longer wavelength and have relatively lower absorption by epidermal melanin, which can make them particularly useful when treating deeper skin tones with appropriate settings.
Alexandrite lasers use a shorter wavelength with strong melanin absorption and are commonly used for hair reduction in lighter skin types.
IPL, or intense pulsed light, can also be used for hair reduction, although technically it isn’t a laser. Rather than producing a single laser wavelength, IPL uses a broader spectrum of light.
The appropriate technology and treatment parameters depend on factors including your skin type, hair colour and the area being treated. This is why proper assessment matters.
How laser compares with other hair removal methods
Shaving and depilatory creams provide temporary hair removal without producing a lasting effect on the follicle. Once the hair grows again, the process needs to be repeated.
Waxing and threading remove the hair from the root, so their results generally last longer than shaving, but the follicle remains capable of producing another hair.
Electrolysis works differently. It treats individual follicles using an electrical current and can achieve permanent hair removal when a follicle is successfully treated. Because follicles are treated individually, however, electrolysis can be a considerably slower process when treating larger areas.
Laser uses light energy absorbed by melanin to thermally damage hair follicles and can treat many follicles across a larger area much more efficiently.
A successful laser course can permanently damage many of the treated follicles and produce a substantial long-term reduction in hair growth, although complete permanent removal of every hair cannot be guaranteed.
Skin and hair type considerations
Skin tone is an important factor in both treatment safety and effectiveness.
Because laser hair reduction relies on melanin as its target, the treatment needs to deliver sufficient energy to the pigment associated with the hair while limiting unwanted heating of melanin within the surrounding skin.
This becomes particularly important in deeper skin tones, where there is more epidermal melanin competing for the laser energy. Appropriate wavelength selection, treatment settings and cooling are therefore important.
Hair colour matters as well. Darker hairs generally provide more pigment for the laser to target, while blonde, red, grey and white hairs may respond less effectively depending on the amount and type of pigment present.
This is why there isn’t one set of laser parameters that is appropriate for everybody. Your skin type, hair characteristics and treatment area all need to be considered.
Why treatment settings matter
There is an important distinction between having laser treatment and having effective laser treatment.
For a follicle to be successfully damaged, sufficient thermal energy needs to reach the structures responsible for producing hair. If the follicle isn’t heated sufficiently, the treatment may not produce the desired degree of lasting damage.
That doesn’t mean simply turning the laser up as high as possible. Excessive or inappropriate energy can increase the risk of damaging the surrounding skin.
Effective treatment is about balancing the wavelength, energy, pulse duration, spot size, cooling and other treatment parameters according to the individual being treated.
This is one of the reasons I believe the experience of the clinician and the quality of the technology matter just as much as the fact that a treatment is described as “laser hair reduction”.
What results should you realistically expect?
The goal of treatment is a significant, lasting reduction in hair growth.
When follicles are successfully treated, some can be permanently damaged and cease producing hair. Across a treatment area, however, we can’t guarantee that every follicle will respond in exactly the same way or that no new hair growth will ever occur.
Hormonal changes can also influence hair growth over time, particularly in some areas of the body. This can affect the amount of regrowth a person experiences and whether occasional maintenance treatments are useful.
So I don’t think the right expectation is that every single hair will disappear forever.
A better expectation is that a properly planned and delivered course should substantially reduce the amount and density of hair growing in the treated area, with some clients requiring occasional maintenance depending on their individual response.
Frequently asked questions
How many sessions does laser hair reduction take?
Many initial courses involve approximately six to eight sessions, but there isn’t one number that’s right for everybody. Treatment area, hair growth cycle, hair characteristics, skin type and individual response all influence the number and spacing of treatments. Your treatment plan should be determined following an assessment rather than assuming a fixed number in advance.
Does laser hair reduction hurt?
Most people describe the sensation as brief heat or a snapping feeling against the skin. Comfort varies according to the area being treated, individual sensitivity, the technology being used and treatment parameters.
Is laser hair reduction permanent?
Laser treatment can permanently damage individual hair follicles so that they no longer produce hair. What we can’t guarantee is permanent elimination of every hair within a treatment area.
This is why the overall outcome is more accurately described as long-term or permanent hair reduction. A successful course can produce a significant and lasting decrease in hair growth, although some clients may experience regrowth or benefit from occasional maintenance over time.
Why can hair grow back after laser treatment?
There are several possible reasons. Not every follicle is in the same growth phase when a treatment is performed, some follicles may respond differently to treatment, and hormonal changes can influence hair growth over time.
Treatment parameters also matter. The follicle needs to receive sufficient thermal energy to produce lasting damage while the surrounding skin is protected.
This is why laser hair reduction is delivered as a properly planned course rather than a single treatment.
Who isn’t a good candidate for laser hair reduction?
People with very light, grey or white hair generally see limited results because there may not be enough melanin within the hair for the laser to effectively target.
Other factors can also affect suitability, which is why your skin type, hair colour, treatment area and relevant medical history should be assessed before treatment.
The bottom line
Laser hair reduction can deliver a significant and genuinely lasting reduction in unwanted hair. Successfully treated follicles can be permanently damaged so that they no longer produce hair.
The distinction is that we can’t promise permanent elimination of every hair.
For me, that is the more useful way to explain the treatment: understand what the technology can genuinely achieve, use appropriate technology and treatment parameters, and set realistic expectations from the beginning.
If you’re considering laser hair reduction and would like to understand what may be achievable for your particular skin and hair type, the team at Rejuvenation Clinics of Australia can help at our Sydney CBD and Chatswood clinics.
