How LED Light Therapy Works on Skin, and What It Cannot Do
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LED light therapy has moved from clinic rooms into people's bathrooms, and the marketing has moved faster than most readers' understanding of it. It is worth knowing what the light is actually doing, because that also explains what it is not doing.
The mechanism, in plain terms
The field's name is photobiomodulation. A 2024 continuing-education review in the Journal of the American Academy of Dermatology sets out the accepted account: light in the red and near-infrared range is absorbed by cytochrome c oxidase, an enzyme in the mitochondria, and that absorption changes cell signalling and energy production (Maghfour, 2024). A 2023 review in Photobiomodulation, Photomedicine and Laser Surgery covers the signalling pathways this sets off in more detail (Barolet, 2023).
The short version: the light is not heating the skin and it is not removing anything. It is absorbed by a specific molecule inside the cell, and the cell's behaviour shifts as a result. That is why wavelength matters more than brightness, and why a red bulb from a hardware shop is not the same thing.
Different wavelengths, different targets
Blue light around 415nm is absorbed by porphyrins produced by the bacteria associated with acne. Red light around 630nm and near-infrared around 830nm penetrate further and are the wavelengths studied for the appearance of ageing skin and for pain. The second part of that JAAD review runs through where the clinical evidence sits for each application in dermatology (Mineroff, 2024).
What it cannot do
It is not a substitute for anything medical. It does not replace a prescription where one is needed, it does not treat a diagnosis, and a device sold for home use is generally lower powered than one used in a clinic. The research that exists is mostly on specific devices, wavelengths and doses, so results from one study do not automatically transfer to another machine.
We sell these devices and we would still rather you read the papers than take our word for it. Every source above is linked.
