Blue plus red light against acne: the classic randomised trial
Short answer
In this randomised trial, 107 people with mild to moderate acne used blue light, blue-plus-red light, white light or benzoyl peroxide for 12 weeks. Blue-plus-red light reduced inflammatory spots by 76% on average, better than white light throughout and better than benzoyl peroxide at weeks 8 and 12, with no significant short-term side effects.
- Study
- Papageorgiou P, Katsambas A, Chu A. Br J Dermatol. 2000;142(5):973-8.
- Design
- Randomised trial, observer-blinded
- People
- 107
- Topic
- Acne
Why it matters
This is the trial most often cited for combining 415 nm blue and red light for acne.
What they did
- Randomised 107 people to four groups: 415 nm blue, 415 + 660 nm blue-red, cool white light, or 5% benzoyl peroxide.
- Light groups treated daily for 15 minutes with portable sources.
- Assessed every four weeks, observer-blinded for light groups.
What they found
- Blue-red light improved inflammatory lesions by 76% at 12 weeks.
- It beat white light at every point and benzoyl peroxide at weeks 8 and 12.
- Comedones improved 58%, though differences were not significant.
What it cannot tell you
- Benzoyl peroxide group could not be blinded.
- Blue light alone caught up with blue-red by week 12.
- Older light sources, not modern masks.
Takeaway
Blue plus red light had solid early evidence for mild to moderate inflammatory acne. Devices with 415 nm blue and red light match this study most closely.
Matching devices
Devices whose published technology and wavelengths match this study (415 nm blue + red): CurrentBody Series 3, Dr. Dennis Gross FaceWare Pro and Shark CryoGlow. Partly matching: Dr. Renú SpectraLift and Omnilux Contour. None of them was the device tested unless the study names it.
Not medical advice. Summary based on the published abstract; read the full paper for detail.