Quick answer: LED masks use different colors because each color is a different wavelength of light, and each wavelength reaches skin in a different way. Red light (about 630–660 nm) and near-infrared light (about 830 nm) have the most research for fine lines and skin texture. Blue light (about 415 nm) is used for breakouts because it acts on acne-causing bacteria. Green light (about 520 nm) is the least studied and is mostly marketed for uneven tone.
How LED light therapy works
LED (light-emitting diode) therapy uses low-level visible and near-infrared light. It does not use UV light and it does not heat the skin the way a laser or a radiofrequency (RF) device does. Instead, specific molecules in the skin absorb the light and respond to it, a process researchers call photobiomodulation. Which molecules absorb the light depends on the wavelength, and that is why the color matters.
If you are new to LED masks, start with our guide on how LED face masks work and what the research shows.
Red light therapy: the most studied color for fine lines
Red light sits at roughly 630–660 nm and is often paired with near-infrared light (around 830 nm), which reaches slightly deeper. These wavelengths are absorbed by cells' energy-producing structures, and studies link them to collagen support and smoother texture.
In a controlled trial of 136 volunteers, twice-weekly sessions of red and near-infrared light improved skin complexion and skin roughness and increased collagen density measured by ultrasound, compared with untreated controls (Wunsch & Matuschka, 2014). Results built up over weeks of consistent use, not after a single session.
Best for: fine lines, dullness, rough texture, and as a calming step after other treatments.
Blue light therapy: aimed at breakouts
Blue light at about 415 nm is absorbed by porphyrins, compounds made by the bacteria involved in acne. When these compounds absorb blue light, they release molecules that are harmful to the bacteria. In a small clinical study, combining blue (415 nm) and red (633 nm) LED sessions reduced acne lesion counts in people with mild to severe acne (Goldberg & Russell, 2006).
You may also see blue light therapy used in dermatology clinics for photodynamic therapy (PDT). There, a light-sensitizing medicine is applied to the skin first, and blue light activates it to treat precancerous spots called actinic keratoses, some of which can develop into skin cancer if left untreated. That is a medical procedure done by a dermatologist and is different from using an at-home LED mask.
Blue light also has limits. A 2024 review of blue light and skin notes that visible light, including blue light, can trigger pigmentation in medium and darker skin tones. If you have melasma or are prone to dark spots, talk to a dermatologist before using blue light, and always protect your eyes.
Best for: oily, breakout-prone skin, as a complement to (not a replacement for) an acne routine your dermatologist recommends.
Green light therapy: the least evidence
Green light (around 520 nm) is often marketed for redness and uneven tone. Compared with red and blue light, there are far fewer controlled studies on green light for skin, so it is best treated as an optional extra rather than a main reason to choose a mask.
Which color should you use?
| Goal | Color to look for | Strength of evidence |
|---|---|---|
| Fine lines, texture, dullness | Red, often with near-infrared | Strongest of the LED colors |
| Breakouts | Blue (often combined with red) | Moderate, mostly small studies |
| Uneven tone or redness | Green or amber | Limited |
For a step-by-step comparison of masks, see how to choose an LED face mask.
How often to use an LED mask
Most at-home masks are designed for short sessions several times a week. The right session length and frequency depend on the device, so follow your mask's instructions rather than a general rule. Consistency matters more than session length: the studies above ran for weeks, with sessions repeated on a schedule.
Safety: who should check first
- Eyes: keep your eyes closed or use the eye protection that comes with your device, especially with blue light.
- Light-sensitizing medications: some acne and antibiotic medications make skin more sensitive to light. Ask your doctor or pharmacist before starting.
- Pigmentation concerns: if you have melasma or get dark spots easily, ask a dermatologist which colors are right for you.
- Seizure disorders, pregnancy or active skin conditions: check with your doctor first.
LED and RF: how they fit together
LED light and radiofrequency work differently. LED light does not heat the skin, while RF devices gently warm the deeper layers of skin to support collagen. Many people use LED for tone and texture and an at-home RF device for firmness. If you are comparing device types, our overview of RF, LED and microcurrent devices explains which one suits which goal, and you can browse Nebulyft at-home skin devices.
Frequently asked questions
What does green light therapy do for skin?
Green light is marketed for redness and uneven tone, but it has much less research behind it than red or blue light.
Is blue light or red light better for acne?
Blue light targets acne-causing bacteria, and red light helps calm the skin. Studies that combined both colors showed fewer breakouts than before treatment.
Can I use red light every day?
Follow your device's instructions. Most routines use several sessions a week, and results build over weeks.
Sources
- Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomedicine and Laser Surgery, 2014. PubMed
- Goldberg DJ, Russell BA. Combination blue (415 nm) and red (633 nm) LED phototherapy in the treatment of mild to severe acne vulgaris. Journal of Cosmetic and Laser Therapy, 2006. PubMed
- Blue Light Effects on the Skin: A Post-2015 Update. Journal of Drugs in Dermatology, 2024. JDD
- Phototherapy with Light Emitting Diodes: Treating a Broad Range of Medical and Aesthetic Conditions in Dermatology. Journal of Clinical and Aesthetic Dermatology, 2018. PMC
This article is for general education and is not medical advice. If you have a skin condition or take medication, talk to your doctor before starting light therapy.
