Red Light Therapy for Acne: 5 Trials, the Only Sham One Added Blue

22 Oct 2026·HealthyMag Editorial Team

A white bathroom shelf with a container and a folded towel lit by soft blue light

Quick Answer: Red light on its own has the thinnest evidence of the acne lights. We found 5 randomised trials of home or portable red light for acne, and only 1 compared it with a sham device: a 2013 double-blind trial of 35 people, in which the active device shone blue light (420 nm) and red light (660 nm). Inflammatory spots fell 77% by week 12, with no significant change on the sham. The one trial of red light alone compared the treated side of the face with an untreated side, not a sham. FDA’s over-the-counter acne code is itself written for devices that emit “in the red and blue region of the spectrum.” The 2016 Cochrane review found that “high-quality evidence on the use of light therapies for people with acne is lacking,” and the 2024 American Academy of Dermatology guideline makes its strong recommendations for creams and pills, not light.

Acne is one of the most searched reasons for red light therapy, and most of the pages that answer it sell a mask. This page goes through the trials one by one, says what light each of them used, and then reads the FDA code the devices are cleared under. Our red light therapy benefits page covers the other uses, and our red light therapy mask page covers wrinkle masks and their clearances.

The 5 trials, and what light each used

Trial	People	Light	Compared with	Result
Papageorgiou 2000, Br J Dermatol	107	Blue 415 nm + red 660 nm, portable, 15 min daily	Blue alone, cool white light, benzoyl peroxide	Inflamed spots 76% better at 12 weeks; ahead of blue at weeks 4 and 8, not 12
Na and Suh 2007, Dermatol Surg	28	Red alone, portable, 15 min twice daily for 8 weeks	Untreated side of the same face	Treated side better at week 8 (p<.005)
Kwon 2013, Br J Dermatol	35	Blue 420 nm + red 660 nm, home device, 2.5 min each twice daily for 4 weeks	Sham device, double-blind	Inflamed spots down 77%, non-inflamed 54% at week 12; no significant change on sham
Li 2022, Photodermatol Photoimmunol Photomed	28	Red alone	Blue alone	Total spots 36.2% vs 30.7% better, not significantly different
Friedmann 2026, Dermatol Surg	23 completed	Red 660 nm + blue 415 nm, home, daily for 8 weeks	Blue 415 nm alone, open label	No significant difference between groups in spot counts

We searched PubMed on 22 October 2026 for randomised trials of red light for acne, with and without blue light, and these are the five that used a home or portable red light source. Clinic trials of photodynamic therapy, where a drug is put on the skin before the light, are a different treatment and are covered further down.

The only sham-controlled trial used blue as well as red

The strongest design in the list is the 2013 Korean trial. Thirty-five people with mild to moderate acne were randomly assigned to a home LED device or a sham device. The active group shone 420 nm blue light and 660 nm red light on the forehead and cheeks, 2.5 minutes each, twice a day for four weeks. At the 12-week visit, inflamed spots had fallen by 77% and non-inflamed spots (blackheads and whiteheads) by 54% in the treatment group, and “no significant difference was observed in the control group.” Skin biopsies showed smaller oil glands and lower levels of inflammatory markers. No serious side effects were reported.

That is a good result, but it is a result for a blue-and-red device. It does not tell you what red light does on its own, because no arm of the trial used red alone.

Red light alone: one split-face trial, one head-to-head

Two trials did test red light without blue:

Na and Suh 2007. Twenty-eight people used a portable red light device on one side of the face for 15 minutes twice a day for eight weeks, leaving the other side untreated. By week 8 the treated side had improved significantly more than the untreated side (p<.005). The authors called it “a new therapeutic option.” The trial was single-blinded, and the comparison was an untreated half-face, so it cannot separate the light from the attention and routine of a twice-daily treatment.
Li 2022. Twenty-eight people were randomised to red light or blue light. Two weeks after the last session, total lesions had improved by 36.2% with red and 30.7% with blue, and inflamed lesions by 51.5% and 26.4%, with none of the differences statistically significant (all p>.05). The authors noted adverse reactions “distinctly in the BL group.” There was no sham or untreated group.

Neither of these is the trial that would settle the question, a red-only device against a sham device. We did not find one.

Red plus blue against blue alone: the gain faded

Two trials asked whether adding red to blue light helps:

Papageorgiou 2000. 107 people were randomised to blue light, mixed blue and red light, cool white light or 5% benzoyl peroxide cream, using portable lamps for 15 minutes a day. After 12 weeks the blue-red group had a mean 76% improvement in inflamed spots (95% confidence interval 66 to 87). That was better than blue light at weeks 4 and 8 but not at week 12, better than benzoyl peroxide at weeks 8 and 12, and better than white light at every visit. For blackheads and whiteheads the blue-red result (58%) was not significantly better than the other treatments.
Friedmann 2026. In an open-label home trial, 23 people completed eight weeks with a 660 nm red plus 415 nm blue device or a 415 nm blue device. Both reduced inflamed spots, but “no significant between-group difference in total, inflammatory, or noninflammatory lesion reduction occurred at any timepoint.” The red-blue group did better on the investigator’s overall rating at week 8.

What the FDA code for home acne devices says

Over-the-counter acne light devices are cleared under FDA product code OLP, regulation 21 CFR 878.4810. FDA’s classification entry describes the device this way: it “is intended to emit energy in the red and blue region of the spectrum, specifically indicated to treat mild to moderate acne vulgaris.”

On 22 October 2026 FDA’s 510(k) database held 51 clearances under code OLP, from 2009 to 2026. Eight of them have “mask” in the device name.
A clearance is tied to the use in the filing. Most red light masks are cleared, if at all, under a different code for wrinkles (OHS), which our mask page counts. A wrinkle clearance is not an acne clearance.
Many red light products are not cleared at all. Under the infrared heating lamp code (ILY), which has been exempt from 510(k) since 2019, a device can be listed with FDA without any premarket review.

Photodynamic therapy is a clinic treatment

Much of the acne light research is about photodynamic therapy (PDT): a doctor applies aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) to the skin, waits, and then shines red or blue light to activate it. This is not a home treatment, and it is not what an LED mask does.

The 2016 Cochrane review combined three trials with 360 people with moderate to severe acne and found MAL-PDT activated by red light “was no different to placebo cream plus red light” for inflamed or non-inflamed spot counts, which it rated moderate-quality evidence. Both groups got the red light, so adding the drug made no measurable difference to spot counts. The review’s overall conclusion was “low certainty of the usefulness of MAL-PDT (red light) or ALA-PDT (blue light) as standard therapies for people with moderate to severe acne.”

What the reviews and guidelines say

Cochrane 2016 included 71 trials with 4,211 people. Most were small (median 31 people), two thirds were industry-sponsored, and “less than half of the studies performed assessments later than eight weeks after final treatment.” It concluded: “High-quality evidence on the use of light therapies for people with acne is lacking.”
A 2022 network meta-analysis done for the UK’s National Institute for Health and Care Excellence (NICE) pooled 179 trials. For mild to moderate acne, “photochemical therapy (combined blue/red light)” cut total lesions by 35.36% more than placebo (95% credible interval 17.75 to 53.08), in the same range as a retinoid combined with benzoyl peroxide (26.16%). The authors added that “uncertainty in findings was high, in particular for chemical peels, photochemical therapy and photodynamic therapy.” NICE’s first-line recommendation is a fixed combination of topical treatments.
The American Academy of Dermatology’s 2024 guideline makes 18 recommendations. The strong ones are for benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline, with isotretinoin for severe or scarring acne. Light therapy is not among the treatments the guideline’s summary lists.

Acne scars are a different treatment

The trials above measured active spots, not scars. Trials for atrophic (pitted) acne scars mostly test ablative fractional lasers in a clinic. A 2024 meta-analysis of eight studies with 418 patients compared fractional CO₂ and Er:YAG lasers and found CO₂ more effective, with more pain and longer redness. We found no sham-controlled trial of a home red LED device for acne scars.

If you want to try light for acne

Match the device to the trials. The positive home trials used blue light near 415 to 420 nm together with red near 660 nm. A red-only panel or mask has the least evidence for acne.
Check the clearance code. In FDA’s 510(k) database, an acne device should show product code OLP. A wrinkle code (OHS) or a heating lamp listing (ILY) is not an acne clearance.
Give it 8 to 12 weeks, and keep your treatment. The trials ran 4 to 12 weeks, and few followed people afterwards. Light was tested as an add-on or alternative for mild to moderate acne, not as a replacement for treatment of severe or scarring acne.
Protect your eyes. Follow the device’s goggles or eye-closure instructions, and see our red light therapy dangers page.

FliKEZE PhotonMask Quint. An LED face mask that its product page lists with blue light at 415 nm and red light at 660 nm, the same pairing as the home acne trials above, plus yellow, green and near-infrared settings. This is a paid placement, not a recommendation, and none of the trials above tested this mask. We found no 510(k) clearance under the FliKEZE or PhotonMask names, including under the acne code OLP (openFDA, 22 October 2026). FDA’s establishment listing for a Chinese manufacturer that also lists FliKEZE’s NeoBack and SpectraWrap names a “PhotonMask II” under the infrared heating lamp code, without a 510(k) number. The product page does not state the light’s output at the skin.

View on FliKEZE

Sponsored link — we may earn a commission at no extra cost to you. If you take isotretinoin, a tetracycline or another medicine that makes you sensitive to light, or have an eye condition, ask your doctor or pharmacist before using a light mask.

Who should see a doctor first

Anyone with acne that is leaving scars, is deep and painful (nodules or cysts), or is affecting their mood. The AAD strongly recommends isotretinoin for acne that is severe, scarring or causing psychosocial burden.
Anyone taking a medicine that makes skin or eyes sensitive to light.

Frequently Asked Questions

Does red light therapy help acne?

Possibly, but the evidence for red light alone is thin. The one trial of red light alone compared the treated half of the face with an untreated half and found the treated side better at 8 weeks. The only sham-controlled home trial used blue and red light together, and found a 77% drop in inflamed spots at 12 weeks.

Is red or blue light better for acne?

In a 2022 trial of 28 people, red and blue light gave similar results (36.2% vs 30.7% improvement in total spots, not significantly different), with more side effects in the blue group. Most of the positive home trials combined the two.

Does red light therapy help acne scars?

We found no sham-controlled trial of a home red LED device for acne scars. Trials for pitted acne scars mostly test fractional CO₂ and Er:YAG lasers in a clinic.

How long does red light therapy take to work for acne?

The trials ran 4 to 12 weeks. In the largest one, red plus blue light was ahead of blue light alone at weeks 4 and 8, but the two had caught up by week 12.

Is red light therapy FDA approved for acne?

Acne light devices are cleared, not approved, under FDA code OLP, which is written for devices that emit red and blue light. FDA’s database listed 51 clearances under that code on 22 October 2026. A red light mask cleared for wrinkles is not cleared for acne.

Can red light therapy make acne worse?

None of the five trial summaries above reports acne getting worse, and the 2013 sham-controlled trial reported no serious side effects. The 2022 red-versus-blue trial reported more adverse reactions with blue light. Cochrane rated the evidence on side effects as very low quality.

The Bottom Line

Red light for acne mostly means red and blue light together. The home trials with the best results, including the only one against a sham device, used both, and FDA’s over-the-counter acne code is written for both. Red light alone has one split-face trial and one small head-to-head against blue light. Cochrane calls high-quality evidence “lacking,” and the main dermatology guidelines put creams and pills first. If you try a device, pick one with blue light and an acne (OLP) clearance, and use it alongside your treatment, not instead of it.

Sources

Kwon HH, et al. The clinical and histological effect of home-use, combination blue-red LED phototherapy for mild-to-moderate acne vulgaris in Korean patients: a double-blind, randomized controlled trial. Br J Dermatol. 2013;168(5):1088-94. PubMed 23278295. Checked 22 October 2026.
Papageorgiou P, Katsambas A, Chu A. Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris. Br J Dermatol. 2000;142(5):973-8. PubMed 10809858. Checked 22 October 2026.
Na JI, Suh DH. Red light phototherapy alone is effective for acne vulgaris: randomized, single-blinded clinical trial. Dermatol Surg. 2007;33(10):1228-33. PubMed 17903156. Checked 22 October 2026.
Li J, et al. Comparison of red light and blue light therapies for mild-to-moderate acne vulgaris: a randomized controlled clinical study. Photodermatol Photoimmunol Photomed. 2022;38(5):459-464. PubMed 34981580. Checked 22 October 2026.
Friedmann DP, et al. Comparing a red and blue light-emitting diode light device with an existing blue light device for at-home treatment of inflammatory acne: an open-label randomized-controlled trial. Dermatol Surg. 2026;52(7):687-691. PubMed 41886698. Checked 22 October 2026.
Barbaric J, et al. Light therapies for acne. Cochrane Database Syst Rev. 2016;9:CD007917. PubMed 27670126. Checked 22 October 2026.
Mavranezouli I, et al. A systematic review and network meta-analysis of topical pharmacological, oral pharmacological, physical and combined treatments for acne vulgaris. Br J Dermatol. 2022;187(5):639-649. PubMed 35789996. Checked 22 October 2026.
Reynolds RV, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024;90(5):1006.e1-1006.e30. PubMed 38300170. Checked 22 October 2026.
Liu F, et al. Efficacy and safety of CO2 fractional laser versus Er:YAG fractional laser in the treatment of atrophic acne scar: a meta-analysis and systematic review. J Cosmet Dermatol. 2024;23(9):2768-2778. PubMed 38733085. Checked 22 October 2026.
U.S. Food and Drug Administration. Product classification, code OLP: Over-the-counter powered light based laser for acne, 21 CFR 878.4810. FDA classification database; 510(k) count of 51 from openFDA. Checked 22 October 2026.
U.S. Food and Drug Administration. Establishment registration and device listing, proprietary name “PhotonMask” (product code ILY). openFDA. Checked 22 October 2026.
FliKEZE. PhotonMask Quint product page (wavelengths as listed by the seller). flikeze.com. Checked 22 October 2026.

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making any health decisions. Content reviewed by the HealthyMag Editorial Team.