Blue vs Red Light Therapy: Which Colour Does What?
Blue vs red light therapy comes down to where each colour works and what it does there: blue light acts at the surface of the skin, mainly on the bacteria linked to acne spots, while red and near-infrared light reach deeper and are studied for lines, texture and collagen. In the acne trials, red mostly appears as blue's partner. Below: how each colour works, what the trials used, how to combine red and blue light therapy, which colour suits darker skin or evening use, and how our mask's two modes map onto the research.
Key takeaways
- In a 2000 trial of 107 people, daily 15-minute sessions of mixed blue and red light cut inflamed acne spots by 76% after 12 weeks. Papageorgiou, 2000
- A 2025 review of 6 home LED trials with 216 people found inflamed spots 45.3% lower than in the control groups. Ershadi, 2025
- Blue light works at the surface because porphyrins made by acne bacteria absorb it, and the reaction damages the bacteria. Ablon, 2018
- In a 2014 trial completed by 128 people, blinded experts rated wrinkles better in 69% to 75% of those in the two light groups, against 4% of untreated controls. Wunsch, 2014
- The American Academy of Dermatology says visible light is "not effective against blackheads, whiteheads, acne cysts, or nodules." AAD
Blue vs red light therapy: what is the difference?
Blue light works near the surface and is used mainly for inflamed acne spots. Red and near-infrared light travel further into the skin and are studied mainly for lines, texture and collagen, with red also used as blue's partner in acne trials.
| Colour | Wavelengths in the trials | Where it acts | Main research use | Kivorla devices |
|---|---|---|---|---|
| Blue | About 410 to 445 nm | At the surface | Inflamed acne spots | Mask blue mode: 460 nm. Panel: 480 nm |
| Red | 611 to 670 nm | Deeper than blue | Lines, texture, collagen; blue's partner for acne | Mask red mode: 665 nm. Panel: 630, 660, 670 nm |
| Near-infrared | 830 nm in the skin trials | Deeper still | Skin ageing, with or instead of red | Mask: 850 nm in both modes, 1064 nm in the red mode. Panel: 810, 830, 850, 1060 nm |
Bacteria in acne spots make porphyrins, which absorb strongly in the 400 to 450 nm region. Bhargava, 2020 Hit by blue light, they form free radicals that damage the bacteria, a process a 2018 review calls "endogenous photodynamic therapy". Ablon, 2018
Red and near-infrared light act on the cells themselves. Their main target is "cytochrome c oxidase in mitochondria", which leads to more ATP and calmer inflammatory signalling. Hamblin, 2017 Much of this mechanism work comes from cell and animal studies.
A computer model of skin found blue light is absorbed close to the surface, while red and near-infrared travel further. Ash, 2017 For the full spectrum, see our guide to LED light therapy colours.
Is blue or red light better for inflamed acne spots?
Blue is the colour most linked to acne, and red mainly appears in acne trials alongside blue. In the best-known trial, blue plus red worked faster than blue alone, and the two were level by week 12.
That trial gave 107 people with mild to moderate acne blue light, mixed blue and red light at 415 and 660 nm, cool white light, or 5% benzoyl peroxide cream for 12 weeks. Papageorgiou, 2000
- Blue plus red: inflamed spots improved by 76% at week 12.
- Against blue alone: better at weeks 4 and 8, level at week 12.
- Against benzoyl peroxide: better at weeks 8 and 12.
- Against white light: better at every visit.
The authors reported "no significant short-term adverse effects". The 2025 review pooled 6 randomised trials of home LED devices in people aged 12 to 50, and combined blue and red appeared to do better than one colour, based on one comparison. Ershadi, 2025 The AAD says blue, red, or blue and red light "can treat pimples", and results vary from person to person. AAD Our red light therapy for acne guide covers spots in more detail.
Can you use red and blue light therapy together, or on alternate days?
Yes, trials did both: some mixed blue and red light in the same session, and others alternated the two colours from one session to the next. Both patterns lowered inflamed spots.
Mixed in one session. A double-blind trial gave 35 people a home device with 420 nm blue and 660 nm red, or a sham device, twice a day for 4 weeks. Kwon, 2013 By week 12, inflamed spots had fallen by 77% and non-inflamed spots by 54%. The sham group showed no significant change.
Alternating sessions. In a study summarised in the 2018 review, 22 people had 415 nm blue and 633 nm red on alternate sessions, twice a week for 4 weeks. Ablon, 2018 Spots fell by 46% at week 4 and 81% at week 12, with no control group. A second study used the same pattern in 24 people with skin type IV, and inflamed spots fell by 77.9%.
As for which colour comes first, the alternating trials gave each colour its own session, so that is the simplest pattern to copy. Our mask's blue mode is blue plus near-infrared, not blue plus red. To get both colours, alternate the blue mode and the red mode on different sessions or days, and count both modes together against the manual's weekly limits. Our red and blue light therapy mask guide sets out a sample week.
Which colour helps fine lines, texture and collagen?
Red and near-infrared. The skin quality trials used these colours, and both blinded ratings and ultrasound scans moved in their favour.
In one trial, 128 adults completed red light or a broader light range from whole-body units, twice a week for 30 sessions, or were untreated controls (not randomised). Wunsch, 2014
- Wrinkles: rated better by blinded experts in 69% (red) and 75% (broader range), against 4% of controls.
- Collagen: density on ultrasound rose in both light groups and stayed the same in controls.
- Roughness: improved in both light groups and worsened in controls.
The 2018 review also summarises a split-face trial in 76 people given 830 nm, 633 nm, both, or sham light, twice a week for 4 weeks. Ablon, 2018 Skin improved in 95.2%, 72.3% and 95.5% of the light groups, against 13.3% with sham.
More light is not always better. The mechanism review notes "a pronounced biphasic dose response": low doses stimulate cells and high doses can hold them back. Hamblin, 2017
Does blue or red light clear blackheads, whiteheads or acne cysts?
Not reliably: the AAD says visible light is not effective against blackheads, whiteheads, cysts or nodules. Inflamed red spots are where light shows its clearest results.
Non-inflamed spots hold fewer porphyrins, which may explain why they respond less to blue light. Ablon, 2018 In the 2000 trial, blackheads and whiteheads improved by 58% with blue plus red, which was not significantly better than the other active treatments. Across the 2025 review, non-inflamed spots were 47.7% lower than in the control groups.
Cysts and nodules sit deep and can scar. Moderate, severe, cystic, painful or scarring acne needs a dermatologist or GP first, and light then fits as an add-on to the treatment they advise.
What settings did the blue and red light trials use, and how long did results take?
The acne trials ran sessions from twice a week to twice a day for 4 to 12 weeks, and improvement was "typically noted after 4 to 12 weeks". Skin quality trials ran twice a week for 4 weeks up to 30 sessions.
| Trial | Goal | Light | Schedule | Length | Headline result |
|---|---|---|---|---|---|
| Papageorgiou, 2000 | Acne | 415 + 660 nm, mixed | 15 minutes daily | 12 weeks | Inflamed spots down 76% |
| Kwon, 2013 (sham) | Acne | 420 + 660 nm home device | Twice daily | 4 weeks, checked to week 12 | Inflamed down 77% |
| Morton, 2005 (via Ablon) | Acne | 409 to 419 nm | 10 or 20 minutes, 8 sessions | 4 weeks, checked to week 12 | Inflamed down 60% at week 12 |
| Goldberg, 2006 (via Ablon) | Acne | 415 and 633 nm, alternating | 20 minutes, twice weekly | 4 weeks, checked to week 12 | Spots down 81% at week 12, no control group |
| Lee, 2007 (via Ablon) | Skin quality | 830 nm, 633 nm, both, or sham | Twice weekly | 4 weeks | Improved in 95.2%, 72.3%, 95.5%; sham 13.3% |
| Wunsch, 2014 | Wrinkles, collagen | Red, 611 to 650 nm range | 12 to 25 minutes, twice weekly | 30 sessions | Wrinkles better in 69% to 75% |
The 4 to 12 week window comes from the 2025 review. Ershadi, 2025 Mayo Clinic notes that "further study is needed to determine the ideal method, light source and dose". Mayo Clinic
Trial lamps and home devices differ in brightness and distance, so these settings do not convert into a mask or panel session. To stay near the gentler end of the studied range, use a lower brightness and a shorter timer, and with the panel step back from 6 to 12 inches. Take photos in the same light at weeks 4, 8 and 12.
Should you use blue light in the morning and red light at night?
That is a sensible split. Blue light in the evening signals daytime to the body clock, while red light has much less effect on melatonin, so the red mode suits evening sessions.
The mask's blue mode is for skin, not for setting the body clock, so keep it for earlier in the day. See red light therapy in the morning or at night for more on timing. Use either mode on clean, dry skin, and after a morning session apply sunscreen: it goes on after the session, not before.
Is blue light suitable for darker skin or skin that marks easily?
Start with the red mode if your skin darkens easily or you have melasma. Blue light can darken medium and darker skin tones, so if you use the blue mode, keep sessions short, at 50% brightness and earlier in the day.
Our blue light therapy guide explains the pigment research. People who tan easily or have melasma should see a dermatologist first, especially before using the blue mode.
- Skin that marks easily: red mode, 50% brightness, a 5-minute timer in the first week.
- Breakouts plus marks: short blue mode sessions at 50%, earlier in the day; stop if patches darken.
- Panel users: the panel is not for Fitzpatrick skin types V or VI.
Side effects in the trials were mild. In the 2025 review's tables, one trial reported mild dryness in 11% and another dryness or itching in 3%. For marks and patches, see red light therapy for hyperpigmentation. With rosacea, ask a dermatologist before starting.
Can red and blue light reach acne on the back or chest?
The mask covers the face only, so the back and chest need the panel. The closest evidence comes from the facial trials above.
The panel's 480 nm channel is one of its nine wavelengths. The acne trials used blue at about 410 to 445 nm, so treat 480 nm as part of the spectrum rather than a dedicated acne setting, alongside the red channels.
- Back: hang the panel at back height, back towards it, about 12 inches away.
- Chest: hang it at chest height, about 12 inches away, goggles on and eyes closed; never aim it straight at the face.
- Time: 10 to 15 minutes per area, skipping open or picked spots until the skin has closed.
How do you use the Kivorla mask's red and blue modes?
Use the blue mode for breakouts earlier in the day, and the red mode in the evening for lines, texture and skin that marks easily. If you want both colours, give each mode its own session and count them together against the manual's weekly limits.
The 4-Wavelength Red Light Therapy Mask is a cordless, full-face silicone shell with an eye opening and no diodes over the eyes. You set it with the handheld controller or by voice.
- Red mode: 665 nm red with 850 and 1064 nm near-infrared, the colours studied for skin quality.
- Blue mode: 460 nm blue with 850 nm near-infrared. 460 nm sits at the long end of the blue band, and the trials used about 410 to 445 nm, so their numbers are a guide.
- Settings: brightness 50, 70 or 90%; timer 5, 10 or 15 minutes, after which the mask switches off. Start at 50%.
- Weekly limits: 10-minute sessions up to 4 times a week at high brightness, or 15-minute sessions up to 3 times a week after a week of three 10-minute sessions. Never more than 20 minutes a day.
- Sample week: blue mode on two mornings and red mode on two evenings, 10 minutes each.
Keep your eyes closed in both modes and do not look into the light. For the jaw, neck, chest or back, the 9-Spectrum Red Light Therapy Panel carries nine wavelengths from 480 to 1060 nm, each dimmable from 1 to 100%, with goggles and a controller included.
Who should not use blue or red light at home?
Do not use either device if you are pregnant, have epilepsy, have a thyroid condition or take thyroid medication, or take medicine that makes skin sensitive to light. Never use light over broken skin or an open wound.
Some acne medicines, such as doxycycline and retinoid tablets, can make skin more sensitive to light. Our precautions rule out use with photosensitising medication, so check with your pharmacist or doctor before using either device.
The panel manual also rules out use while breastfeeding or preparing for pregnancy, after sunburn on the body in the past 2 weeks, and with seizures triggered by light. The Cleveland Clinic advises home users to "shield your eyes for protection". Cleveland Clinic
Read the precautions before ordering. Standard shipping to the US, UK and Germany is free. Under our return and refund policy, returns are accepted within 30 days: an unopened device with its seals intact is refunded less a 10% restocking fee, and an opened device that is undamaged and complete is refunded less 20%.
Kivorla devices are general wellness devices, not medical devices, and are not intended to treat acne or any skin condition. See a dermatologist or GP for cystic, painful or scarring acne, melasma or rosacea, and keep any treatment they prescribe.