This review explains how laser hair loss treatment is said to work, and gives six possible problems that might mean this costly form of therapy will not save your hair!
For a very long time it’s been known that natural sunlight can be of benefit to the human body. And this is especially true of light that’s in the red end of the spectrum.
So, the lasers used in hair loss treatment emit red light at wavelengths
which are believed to stimulate hair regrowth in one or more of the
Laser hair loss treatment is aimed towards those who have only just begun to lose hair or develop thinning hair, and not really for anyone whose hair loss is already severe.
And, since laser therapy also has a skin healing effect, it can be used to assist recovery of the scalp following hair transplant surgery too.
Note: laser hair loss treatment is also known as low level laser therapy (LLLT), cold laser therapy and laser phototherapy.
Six big risks of laser therapy
Several factors can influence whether or not using laser light to treat hair loss will work. Six of these are explained below:
Measured in milliwatts (mW). Think of power as being the rate of energy flowing per second. The lasers used for hair loss all seem to be 5 milliwatts (mW).
However, there is some debate as to whether or not such lasers can penetrate the skin’s "optical barrier".
Some say it simply depends upon the power output, whereby the more powerful a laser is, clearly the deeper into tissue it will reach.
Obviously clinics and the manufacturers of hair laser comb products have to make sure that their machines won’t harm the patient - that would definitely be bad for business!
But, this could mean that there’s a compromise on laser power level which might be less than optimal.
Measured in joules per unit area (J/cm²). Think of fluence as being the amount of radiant energy hitting per cm² of the scalp surface. The best fluence level to use for hair loss is debatable, but research suggests 3 to 6 joules per cm² might be optimal.
Most companies seem to keep the fluence level of their lasers a closely guarded secret which, to me, suggests there’s real uncertainty as to what level is best to use.
The wavelength said to be of most benefit for hair regrowth is 650 nanometres (nm), which is visible as red light. However, some companies use slightly different wavelengths in an attempt to improve hair regrowth even more.
Laser light is coherent – i.e., the light waves do not scatter because they’re "in phase" with each other. This gives a concentrated beam of light. Other types of light (e.g., LEDs) are non-coherent (or incoherent) – their light particles (photons) are not in phase and so will randomly scatter as soon as they leave the light source.
However, lasers appear to lose their coherence when they enter the body, and this has led to uncertainty about whether the argument for using lasers rather than any other light source is flawed.
Most lasers have very low divergence - they produce a single point of light and don’t spread out and "dilute" the radiation they emit as does diffused light (such as the LED light in the diagram below). This means that they can target specific areas of the scalp efficiently and, therein, may work better.
But, it also means less coverage. So the total duration of treatment might need to be longer to treat the whole scalp (unless the laser device used has a high number of laser diodes and/or uses diffused lasers).
Diffused lasers do have a greater divergence which makes them safer and gives more coverage. And the total duration of treatment can be reduced depending upon other factors such as how strong the lasers are.
Some consider pulsed lasers to be more effective for tissue healing. But, a continuous wave laser works well at reducing inflammation.
So, which type is best for hair loss?
And another thing to consider is that, some pulsed lasers used for hair removal seem to get converted into thermal energy more efficiently than continuous lasers and so, can "kill" hair follicles more effectively. So, use a pulsed laser device and you might risk suppressing your hair follicles rather than stimulating them!
And I would have thought such uncertainty would be enough to put most people off the whole idea (let alone the huge cost involved).
But, if you’re still considering laser therapy for your hair loss, the next page compares clinics with hand-held products.
This is page 1 of 2.
Read next page? Clinics vs. Hair Laser Combs.