Research library
The research behind light therapy
The peer-reviewed studies behind light therapy and our other skin technologies, sorted by topic. Each card shows the study design and key finding, and links to the full paper. These are independent studies, not tests of Project E devices.
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Clinical studies
Low-Level Light Therapy2017
Mechanisms and Applications of the Anti-Inflammatory Effects of PhotobiomodulationReviewReviews how photobiomodulation reduces markers of inflammation in cell, animal and clinical studies.Read the study
Low-Level Light Therapy2011
Low-Level Light Therapy of the Eye and BrainReviewDescribes cytochrome c oxidase as the main light-absorbing enzyme in eye and brain cells, and reviews early evidence for metabolic and antioxidant effects.Read the study
Low-Level Light Therapy2020
The Molecular Mechanisms of Action of Photobiomodulation Against Neurodegenerative DiseasesSystematic reviewLight improved cell survival and mitochondrial function and reduced oxidative stress and inflammation; the authors note the mechanisms need more study.Read the study
Low-Level Light Therapy2014
Low-Level Laser (Light) Therapy in Skin: Stimulating, Healing, RestoringReviewReviews the use of low-level light in skin, including rejuvenation, acne and wound healing.Read the study
Ageing Skin & Rejuvenation2022
Effectiveness of a Radiofrequency Device for Rejuvenation of Aged Skin at HomeSplit-face RCT · home radiofrequency device vs cosmetics alone · 33 women · 12 weeksThe device side improved more than cosmetics alone. This studied radiofrequency, not LED light.Read the study
Ageing Skin & Rejuvenation2011
Objective Assessment of Skin Rejuvenation Using Near-Infrared 1064-nm Neodymium: YAG Laser in AsiansSingle-arm · 1064 nm Nd:YAG laser · 50 Japanese patientsPores, texture and wrinkles improved on imaging analysis. This studied a laser, with no control group.Read the study
Ageing Skin & Rejuvenation2025
Role of Photobiomodulation Application Frequency in Facial Rejuvenation: Randomized, Sham-Controlled, Double-Blind TrialRandomised, sham-controlled, double-blind · 660 nm LED mask · 2 vs 3 sessions a week · 4 weeksPatient satisfaction was higher than with sham; expert ratings of photos did not differ.Read the study
Ageing Skin & Rejuvenation2024
User Reported Satisfaction for Light Emitting Diodes Under-Eye RejuvenationSingle-arm · 633 + 830 nm home under-eye LED device · 11 participants · 6 weeksUsers reported high satisfaction; the measured wrinkle change was small and not statistically significant.Read the study
Ageing Skin & Rejuvenation2007
A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenationSplit-face, double-blind, placebo-controlled · 633 nm red + 830 nm infrared LED · 76 patientsCollagen and elastic fibres increased in all treatment groups on skin biopsy.Read the study
Body Contouring2024
Body Contouring Effects of At-Home Beauty Device Equipped with Suction, Radiofrequency, and EMS FunctionsSingle-arm, untreated calf as control for swelling · home suction, radiofrequency and EMS device · 21 women · 8 weeksCellulite, swelling, elasticity and dermal density improved from baseline; thigh and waist size did not change. This device does not use light.Read the study
Ageing Skin & Rejuvenation2009
Regulation of Skin Collagen Metabolism In Vitro Using a Pulsed 660 nm LED Light Source: Clinical Correlation with a Single-Blinded StudyLab-grown human skin model + split-face, single-blinded clinical study · pulsed 660 nm LED · 12 treatmentsType I procollagen rose 31% and MMP-1 fell 18% in the skin model; most participants had less wrinkle depth and roughness on the treated side.Read the study
Cellular Science2021
Anti-Inflammatory Effects Induced by Near-Infrared Light Irradiation through M2 Macrophage PolarizationCell and mouse study · near-infrared light (700–1,000 nm)Near-infrared light shifted immune cells (macrophages) to an anti-inflammatory state and reduced inflammation in a mouse skin model.Read the study
Cellular Science2019
Mitochondrial Mechanisms of Photobiomodulation in Human Skin CellsRead the study
Low-Level Light Therapy2021
Near Infrared (NIR) Light Therapy of Eye Diseases: A ReviewReviewReviews how near-infrared light acts on cytochrome c oxidase, and the evidence for its use in eye and neurological conditions.Read the study
Cellular Science2007
Melatonin as a principal component of red light therapyHypothesis paperProposes that melatonin may help carry the effects of red light (670 nm, 4 J/cm²); the authors state the idea is untested.Read the study
Acne2021
A Comparative Study Between Once-Weekly and Alternating Twice-Weekly Regimen Using Blue (470 nm) and Red (640 nm) Light Combination LED Phototherapy for Acne VulgarisRandomised · blue 470 nm + red 640 nm LED · once vs twice weekly · 4 weeksBoth schedules improved inflammatory lesions, with no significant difference between them.Read the study
Acne
Efficacy of Low-Level Laser Versus Topical Erythromycin 2% in the Treatment of Inflammatory Acne VulgarisSplit-face: 808 nm laser vs erythromycin 2% · 40 patientsMost side-to-side differences were not significant; fewer relapses on the laser side.Read the study
Acne
The Anti-Acne Effect of Near-Infrared Low-Level Laser TherapySingle-arm · 785 nm laser · 27 womenSebum and lesions fell from baseline; there was no untreated control group.Read the study
Acne
Comparison of Red and Infrared Low-level Laser Therapy in the Treatment of Acne VulgarisSplit-face: 630 vs 890 nm, both with clindamycin 2% · 28 patientsBoth sides improved; the effect cannot be attributed to light alone.Read the study
Ageing Skin & Rejuvenation
Clinical study to evaluate the efficacy and safety of home-used LED and IRED mask for crow’s feet: a multi-center, randomized, double-blind, sham-controlled studyRandomised, double-blind, sham-controlled · 630 + 850 nm home-use mask · 60 participants · 12 weeks25 of 29 participants improved by at least one grade, vs 5 of 30 with a sham mask.Read the study
Ageing Skin & Rejuvenation
Low-level laser therapy for skin rejuvenation: a safe and effective solution backed by data and visual evidenceTwo 660 nm treatment frequencies compared · 30 women · no shamBoth groups improved from baseline, with no significant difference between them.Read the study
Ageing Skin & Rejuvenation
Reverse skin aging signs by red light photobiomodulationSingle-arm · 630 nm LED mask · 20 participants · 3 monthsSeveral objective skin measures improved from baseline; there was no control group.Read the study
Ageing Skin & Rejuvenation
Effects of radiofrequency, electroacupuncture, and low-level laser therapy on the wrinkles and moisture content of the forehead, eyes, and cheekRadiofrequency vs electroacupuncture vs 635 nm laser · 30 participants · 6 weeksSome wrinkle and moisture measures improved from baseline.Read the study
Hair Growth
Impact of Photobiomodulation on the Quality of Life of Men and Women With Androgenetic AlopeciaSingle-arm · 655 nm laser + LED helmet · 85 participants · 12 weeksQuality-of-life scores (Skindex-29) improved; hair density was not measured.Read the study
Hair Growth
Assessment of Effects of Low-Level Light Therapy on Scalp Condition and Hair GrowthSingle-arm · multi-wavelength LED helmet · 50 participants · 24 weeksHair density and thickness improved from baseline; there was no sham control.Read the study
Hair Growth
Efficacy of Low-Level Laser Therapy in Androgenetic Alopecia: A Randomized Controlled TrialRandomised: 655 nm laser comb + 5% minoxidil vs minoxidil alone · 68 patients · 16 weeksDensity rose 14.8% vs 11.4%; the difference was not statistically significant.Read the study
Hair Growth
Efficacy assessment for low-level laser therapy in the treatment of androgenetic alopecia: a real-world study on 1383 patientsReal-world app data · 650 nm helmet · 1,383 patients analysedAbout 80% reported improvement on a composite self-assessment; this was not a controlled trial.Read the study
Hair Growth
Low-Level Light Therapy Downregulates Scalp Inflammatory Biomarkers in Men With Androgenetic Alopecia and Boosts Minoxidil 2% to Bring a Sustainable Hair Regrowth Activity590/870 nm light + 2% minoxidil vs 5% minoxidil vs no treatment · 130 men · 6 monthsResults were observed for light combined with lower-strength minoxidil; the effect of light alone cannot be isolated.Read the study
Hair Growth
Low-level light therapy using a helmet-type device for the treatment of androgenetic alopecia: a 16-week, multicenter, randomized, double-blind, sham device-controlled trialRandomised, double-blind, sham-controlled · 655 nm laser + LED helmet · 60 participants · 16 weeksHair density rose by 41.9 hairs/cm² vs 0.7 with a sham device (P < .001).Read the study
Hair Growth
Efficacy and safety of a low-level laser device in the treatment of male and female pattern hair loss: a multicenter, randomized, sham device-controlled, double-blind studyFour randomised, sham-controlled trials · 655 nm laser comb · 269 participants · 26 weeksTerminal hair density was 15.3 hairs/cm² higher than with sham.Read the study
Hair Growth
The growth of human scalp hair in females using visible red light laser and LED sourcesRandomised, double-blind, sham-controlled · 655 nm laser + LED helmet · 47 women · 16 weeksHair counts improved more than with a sham device.Read the study
