What Is Actually New in Lasers, and What Only Sounds New
The principle underneath every aesthetic laser was published in 1983 and has not been superseded. Almost everything marketed since is an improvement in engineering rather than a new idea, and that is not a criticism: better engineering is what turned a dangerous specialist procedure into a routine one. But it does mean that a device described as revolutionary is usually a refinement, and it helps to know which refinements actually changed outcomes.
The idea underneath every cosmetic laser was published in 1983, and nothing has replaced it since. Almost everything sold since then is better engineering rather than a new idea. That is not a criticism. Better engineering is exactly what turned a risky specialist procedure into an ordinary one. But it does mean that a machine described as revolutionary is usually a refinement, and it helps to know which refinements actually changed anything for patients.
What Is Actually New in Lasers, and What Only Sounds New: the essentials
The short version
Selective photothermolysis: pick a wavelength the target absorbs, pulse it shorter than the target cools
Pick a colour of light your target soaks up, and fire it in a flash shorter than the time that target takes to cool.
Fractional delivery, which cut downtime dramatically
Treating in tiny separate dots instead of the whole surface, which cut recovery time enormously.
Shorter pulses, which made pigment and tattoo clearance more effective
Much shorter flashes, which work better on pigment and tattoo ink.
Cooling, which widened the range of skin types that can be treated safely
Cooling, which made it safe to treat far more skin tones.
New names for existing wavelengths and pulse structures
New brand names for light and settings that already existed.
What does this change about my result or my recovery, specifically
What does this change about my result, or my recovery, specifically?
What has not changed at all
What has not changed at all
Selective photothermolysis remains the whole basis of the field. Choose a wavelength your target absorbs more strongly than its surroundings, deliver it in a pulse shorter than the time the target takes to shed heat, and you destroy the target while sparing the neighbourhood. Every device is an implementation of that sentence.
The whole field still rests on one idea. Choose a colour of light that your target soaks up more than the things around it, deliver it in a flash shorter than the time the target needs to cool, and you destroy the target while leaving its neighbours alone. Every machine ever built is just a way of doing that sentence.
Because the principle is fixed, so are the constraints. Melanin still competes for light in darker skin. Grey hair still has no target. Blood still absorbs where it absorbs. No amount of engineering removes those, and a device that claims to have transcended them is claiming to have changed physics.
Because the idea is fixed, so are its limits. The colour in darker skin still competes for the light. Grey hair still has nothing for the laser to aim at. Blood still soaks up the light it soaks up. No amount of engineering gets round those, and a machine claiming to have beaten them is claiming to have changed physics.
The three changes that really mattered
The three changes that really mattered
First, fractional delivery. Treating the skin in thousands of microscopic columns with untreated tissue between them turned resurfacing from a two-week open wound into a few days of redness, and it did so without changing the wavelength at all. That is the single largest practical advance since the principle itself.
First, treating in dots. Working across the skin in thousands of microscopic dots with untouched skin in between turned resurfacing from a two week open wound into a few days of redness, and it did that without changing the light at all. It is the biggest practical step forward since the original idea.
Second, shorter pulses. Moving from nanosecond to picosecond delivery changed the mechanism for pigment from primarily heating to primarily photomechanical, which improved clearance of some tattoo inks and pigmented lesions and, in some settings, reduced the thermal injury around the target.
Second, much shorter flashes. Going from flashes measured in billionths of a second to flashes a thousand times shorter changed how pigment is dealt with. Instead of mostly cooking the pigment, the light mostly shatters it. That clears some tattoo inks and some pigmented spots better, and in some cases causes less heat damage around the target.
Third, cooling. Contact plates, cryogen spray and cooled sapphire windows protect the epidermis while energy passes through it, which is what made it possible to treat a much wider range of skin types with acceptable risk. It is the least glamorous of the three and arguably the most important for access.
Third, cooling. Chilled contact plates, cold sprays and cooled sapphire windows protect the surface of the skin while the energy passes through it. That is what made it possible to treat a much wider range of skin tones at acceptable risk. It is the least exciting of the three and probably the most important, because it decided who could be treated at all.
What tends to sound newer than it is
What tends to sound newer than it is
Proprietary names for established wavelengths. Handpieces described as a technology in their own right. Claims of no downtime, which usually mean the treatment is gentle enough that its effect is correspondingly modest. And comparisons to surgery, which are the clearest signal to slow down.
Brand names invented for light that already existed. Handpieces described as though they were a technology in their own right. Promises of no downtime, which usually mean the treatment is gentle enough that its effect is gentle too. And comparisons to surgery, which are the clearest possible signal to slow down.
A reasonable test is to ask what a claim would mean physically. If a device is said to tighten deeply with no discomfort and no downtime, ask what is heating what, and to what temperature. Collagen remodelling requires the tissue to reach a particular range, and reaching it is felt. A treatment that is entirely comfortable and requires no recovery has usually not done very much.
A good test is to ask what a claim would actually mean physically. If a machine is said to tighten deeply with no discomfort and no recovery, ask what is heating what, and to what temperature. Rebuilding the fibres in your skin needs the tissue to reach a certain temperature range, and reaching it is something you feel. A treatment that is completely comfortable and needs no recovery has usually not done a great deal.
This is not an argument that discomfort equals effectiveness, which would be its own error. It is an argument that the physics sets a floor, and claims that appear to sit below that floor are worth questioning rather than admiring.
That is not the same as saying pain equals results, which would be its own mistake. It is saying that the physics sets a floor, and claims that appear to sit below that floor are worth questioning rather than admiring.
How to evaluate a new device claim
How to judge a claim about a new machine
Four questions cover most of it, and they are answerable by anyone who understands the device they are selling.
Four questions cover most of it, and anyone who understands the machine they are selling can answer them.
What is it absorbed by, and how deep does it reach? What does it change about my result compared with the previous approach? What does it change about my recovery? And what is the evidence, in people with skin like mine? A clear answer to the fourth is worth more than a clear answer to the first three.
What soaks up this light, and how deep does it go? What does it change about my result compared with what came before? What does it change about my recovery? And what is the evidence in people with skin like mine? A clear answer to that last one is worth more than clear answers to the first three.
It is also worth remembering that the device is not the treatment. The same machine in two pairs of hands produces different results, because the settings, the diagnosis and the decision about whether to treat at all are where the judgement lives. The most consequential upgrade in any practice is usually not the newest machine.
It is also worth remembering that the machine is not the treatment. The same machine in two different pairs of hands gives different results, because the settings, the diagnosis, and the decision about whether to treat you at all are where the judgement sits. The most important upgrade any practice makes is usually not the newest machine.
Questions patients ask
Is a newer laser better than an older one?
Is a newer laser better than an older one?
Not automatically. Newer devices often improve speed, comfort or cooling, but the physics of absorption has not changed. A well-maintained older device used for the right indication outperforms a newer one used for the wrong one.
Not automatically. Newer machines are often faster, more comfortable or better cooled, but what light does to tissue has not changed. A well maintained older machine used for the right job beats a newer one used for the wrong job.
What does picosecond actually change?
What do the very short flashes actually change?
Shorter pulses shift the effect on pigment from mainly heating to mainly mechanical fragmentation, which can improve clearance of some inks and pigmented lesions and may reduce surrounding thermal injury. The benefit varies by target and by study.
They change how pigment is broken up: mostly shattering it rather than mostly cooking it. That can clear some inks and some pigmented spots better, and may cause less heat damage nearby. How much benefit you get depends on what is being treated, and the studies do not all agree.
Is no downtime a realistic claim?
Is no downtime a realistic promise?
It is realistic for genuinely gentle treatments, and those produce correspondingly gentle results, usually over a course. It is not realistic alongside a claim of substantial remodelling in one session.
It is realistic for genuinely gentle treatments, and those give genuinely gentle results, usually over a course of sessions. It is not realistic alongside a promise of major change in one visit.
How do I compare two clinics offering the same treatment?
How do I compare two clinics offering the same treatment?
Ask each what device and settings they would use for your specific concern and skin type, how many sessions they expect, and what they would do if it did not work. The answers differ more than the machines do.
Ask each one what machine and what settings they would use for your particular concern and your skin, how many sessions they expect, and what they would do if it did not work. The answers vary far more than the machines do.
Does the number of lasers a clinic owns matter?
Does it matter how many lasers a clinic owns?
It matters in one specific way: it determines whether they can match a device to your problem and skin, or must adapt your problem to the device they have. It is not a proxy for quality on its own.
It matters in one specific way: it decides whether they can match a machine to your problem and your skin, or have to bend your problem to fit the machine they own. On its own it is not a sign of quality.
Where to go next
Talk it through with a physician first.
Every plan starts with an assessment of your skin, your anatomy and what you actually want to change.
This page is general health information, not medical advice. It cannot tell you whether a treatment is right for you. Approved uses, risks and results differ from person to person, and product labelling changes. Ask us at Dermatology and Laser Centre about your own situation, or make an appointment, and seek urgent care for any serious symptom.
