There is a question we hear a lot. Someone has been looking at LED face masks, noticed that cheaper devices advertise seven colours and wants to know whether more colours means better results. The short answer is NO. The longer answer matters, because a lot of people have spent good money on devices that were never going to do what they hoped.
This is the difference between RGB light and clinical grade LED light therapy. They are not the same thing. One is a cosmetic lighting effect. The other is a therapeutic technology with decades of clinical research behind it.
What RGB light actually is and why it does not work
RGB stands for red, green, blue. It is the same technology used in television screens, stage lighting, disco balls and decorative LED strips. By mixing those three primary colours in different ratios, an RGB system can produce almost any visible colour. That is the only thing it does. It produces colours.
This is why a cheap LED mask can advertise seven colours. Not because it has seven therapeutic wavelengths. It has none. What it has is red, green and blue LEDs mixed in different combinations to display different colours on your face, in exactly the same way a phone screen mixes pixels to show you a photograph. Your phone screen glows too. Neither is doing anything to your skin.
RGB light looks the part. It is colourful, it glows, it photographs well on a bathroom shelf. But strip away the packaging and the language around it and what you have is essentially an expensive torch pointed at your face. The light is decorative. It is doing what decorative light does: it looks good. Nothing more than that is happening.
The packaging will often use words like "photon therapy" or "colour light therapy" which sound scientific without meaning anything specific. What it will not tell you, because it cannot, is which wavelength the light is operating at, how deep it penetrates, or what biological process it is intended to support. Those details do not exist, because the device was not designed around them. It was designed to glow. It is very good at that. That is the entirety of what it does.
The people buying these devices are not naive. They have read about LED light therapy, they know red light is associated with collagen and blue light with acne and they are trying to do something sensible for their skin. The problem is that seeing red coloured light on your face is not the same as receiving red light therapy. A device that produces what looks like red light through RGB mixing may be outputting a completely different wavelength entirely. The colour your eye perceives and the frequency of light hitting your skin are two separate things and it is the frequency that does the work.
This is the core of why RGB face masks frustrate so many people. The expectation is reasonable. The technology behind the product does not match it.
The therapeutic science behind LED light therapy is built entirely on specific, measured wavelengths. Not colours. Not the appearance of colours. Specific wavelengths.
Why the nanometre number is the only number that counts
A nanometre (nm) is a unit of measurement for the wavelength of light. Different wavelengths penetrate the skin to different depths and trigger different biological responses. This is not a marketing claim. It is the basis of decades of photobiomodulation research and it is why LED light therapy has been used in dermatology clinics long before at home devices existed. A peer reviewed clinical study published on PubMed Central confirmed that irradiating skin with LED light at 630nm and 850nm stimulates dermal cells and improves collagen synthesis with wavelength precision central to achieving consistent results.
Red light at 630nm, for example, penetrates into the dermis and may support collagen production. Near infrared light at 850nm goes deeper still, into muscle and connective tissue, where it may support circulation and reduce inflammation. Blue light at 460nm stays close to the surface of the skin, where it may help to address acne causing bacteria. Yellow light at 590nm targets the uppermost layers and may help with redness and uneven skin tone.
Each of those effects depends on the light hitting the skin at the right specific frequency. Move a few nanometres off and the biological target changes. This is why the research is conducted at precise wavelengths and why devices that cannot specify their wavelengths cannot honestly claim to replicate those results.
An RGB device producing what looks like red light may be outputting light anywhere across a broad visible spectrum. A clinical grade LED device producing red light at 630nm is delivering a calibrated frequency to a known depth. These are fundamentally different things.
The four wavelengths in our LED Light Therapy Face Mask
Our LED Light Therapy Face Mask uses four specific, calibrated wavelengths chosen because each one has a clear mechanism and an established body of research behind it.
Blue at 460nm works at the surface of the skin. It targets the bacteria associated with breakouts, making it useful for anyone dealing with congestion or acne prone skin.
Yellow at 590nm sits just below the surface. It may help to calm redness and support a more even skin tone over time, which makes it a practical choice for skin that flushes easily or shows post inflammatory marks.
Red at 630nm reaches into the dermis. It is the most researched wavelength in LED therapy and is associated with supporting collagen production, improving skin firmness and reducing the appearance of fine lines with consistent use.
Near infrared at 850nm goes deepest. It is invisible to the eye, which sometimes surprises people, but it penetrates beyond the skin into muscle and connective tissue. It may support circulation and help with the kind of low-level inflammation that shows up as puffiness or dullness.
The mask contains 240 clinical grade LEDs across 60 chip blocks, with irradiance up to 40 mW/cm2. Those numbers matter too and we will come to them.
Our full LED mask range includes devices using a different set of four wavelengths, including deep infrared at 1072nm, which penetrates even further. All are built around the same principle: specific wavelengths, stated clearly, chosen for a reason.
Why irradiance matters as much as wavelength
Think of it this way: the specific wavelength is the medicine and irradiance is the dose. Getting the medicine right matters. Getting the dose wrong means it does not work. Wavelength tells you which frequency of light is being used. Irradiance tells you how much of it is actually reaching your skin. It is measured in milliwatts per square centimetre (mW/cm2) and it is where many devices that look credible on paper fall short in practice.
A mask can publish the right wavelengths and still deliver almost nothing to your skin if the irradiance is too low. The light has to reach the tissue at a sufficient dose to trigger a cellular response. Too little and nothing happens. This is not a matter of opinion. It is how photobiomodulation works.
When you are comparing devices, irradiance should be stated explicitly in the spec sheet. If it is not there, ask why. A brand confident in its output will publish the number.
How to read a spec sheet before you buy
Most people buying an LED mask look at the price, the number of LEDs and the before and after photographs. These are not the things that tell you whether a device will work.
The questions worth asking are straightforward. What are the exact wavelengths, stated in nanometres? What is the irradiance, stated in mW/cm2? Does the device hold any safety or quality certifications, such as ISO 13485 or CE marking? Is the brand willing to publish this information clearly, rather than burying it in small print or leaving it out entirely?
CE marking and ISO 13485 certification are meaningful because they require documented quality management across manufacturing and testing. They are not marketing labels. They are standards a device has to be independently verified against.
A device that lists its colours but not its wavelengths, or its LED count but not its irradiance, is missing the information you actually need. That absence is itself informative.
You can browse our full LED light therapy range with all specifications published, including wavelengths, irradiance and certifications, so you can compare on the terms that matter.
What this means in practice
If you have been using a multi colour LED mask and not seeing consistent results, the wavelength question is worth revisiting. Visible colour and specific therapeutic wavelength are not the same thing and the gap between them is where a lot of disappointment lives.
This is not about price alone. There are inexpensive devices with calibrated wavelengths and expensive ones without. The spec sheet is what tells you which is which, provided the brand is willing to publish one.
Pure Derma was built on the principle that the proof has to come before the promise. That is why every device we sell comes with its wavelengths, irradiance, LED count and certifications stated clearly. We think you should be able to read a spec sheet and understand exactly what you are buying before you spend a penny.
If you want to understand more about how LED light therapy works in practice, our guide to choosing an LED face mask covers what to look for across the category. And if you have a question about any of our devices, our team is available seven days a week at help@purederma.co.uk.
Light is precise. The devices that use it properly should be too.
Frequently asked questions
What is the difference between RGB light and LED light therapy?
RGB light mixes red, green and blue LEDs to produce a range of visible colours, in the same way a screen does. LED light therapy uses specific, calibrated wavelengths of light, measured in nanometres, to reach particular depths in the skin and trigger defined biological responses. A device that advertises multiple colours is likely using RGB mixing. A clinical grade LED therapy device will state its wavelengths precisely.
What do the nanometre numbers on an LED mask mean?
Nanometres (nm) measure the wavelength of light. Different wavelengths penetrate the skin to different depths and interact with different tissue targets. Red light at 630nm reaches the dermis and may support collagen production. Near infrared at 850nm goes deeper into connective tissue. Blue at 460nm stays near the skin surface and may address bacteria associated with breakouts. The nanometre number tells you which biological target the light is designed to reach.
Which wavelength is best for anti ageing?
Red light at 630nm is the most researched wavelength for anti ageing applications. It penetrates into the dermis and is associated with supporting collagen production and improving the appearance of fine lines and skin firmness with consistent use. Near infrared light at 850nm complements this by working at a deeper level, supporting circulation and helping with inflammation. Using both together, as in our LED Light Therapy Face Mask, gives a broader range of support than either alone.
How do I know if an LED mask is using the right wavelengths?
Check the spec sheet for wavelengths stated in nanometres and irradiance stated in mW/cm2. A credible device will publish both. Also look for safety and quality certifications such as ISO 13485 and CE marking. If a brand lists colours or LED counts but not wavelengths or irradiance, that information gap is worth taking seriously before you buy.
If you want to see what clinical grade LED therapy actually looks like, you can browse the full Pure Derma LED light therapy range with all wavelengths, irradiance and certifications published. Or if you have a question before you buy, our team is available seven days a week at help@purederma.co.uk.
Written by Kerry, owner of Pure Derma London. Kerry started Pure Derma London after too many years and too much money spent on beauty devices that looked convincing and delivered nothing. She decided to build the brand she had been looking for. Pure Derma is the result.
