Red Light Therapy and Skin Firmness: The Studies

"Skin tightening" is a common marketing phrase for red light devices, but it is not a single measurable outcome in clinical research. Studies of red and near-infrared light on aging skin instead measure specific things — wrinkle depth or volume, skin roughness, elasticity, and collagen density — or rely on participant and investigator ratings. This article summarizes what several of those studies and reviews have reported. It is informational only and makes no claims about results for any individual or device.

What researchers measure

Clinical trials of light therapy for skin aging have used outcomes such as:

• Wrinkle measurements from skin profilometry or 3D imaging
• Elasticity and viscoelasticity, measured with skin-testing instruments
• Collagen density, measured by ultrasound or examined in skin biopsies
• Graded photographs reviewed by blinded evaluators
• Participant satisfaction and quality-of-life questionnaires

Because different studies measure different things, a finding on one outcome (for example, wrinkle volume) does not necessarily mean a change in another (for example, firmness or elasticity).

Selected clinical studies

Split-face trial with sham control (2007)

A randomized, placebo-controlled, double-blinded, split-face study treated 76 people with facial wrinkles using LED devices at 830 nm, 633 nm, both, or a sham light, twice weekly for four weeks with three months of follow-up. The authors reported reductions in wrinkles (up to 36%) and increases in elasticity (up to 19%) compared with baseline in the active-treatment groups, along with increased collagen and elastic fibers in skin samples. No adverse effects were reported.¹ The figures cited are maximum values among the treatment groups, measured against each participant's own baseline.

Controlled trial of red and broadband light (2014)

A prospective, randomized, controlled trial enrolled 136 volunteers, with 113 assigned to one of four light-treatment groups and 23 serving as controls. Participants received treatments twice weekly and were assessed after 30 sessions. The authors reported improvements in skin complexion and feel, reduced skin roughness, and increased ultrasound-measured collagen density compared with controls, and found no advantage of broadband light over red light alone.² The lead author was affiliated with a medical light consulting firm.²

Periocular wrinkle trial (2023)

A split-face randomized trial in 137 women aged 40 to 65 compared red (660 nm) and amber (590 nm) light, one on each side of the face, over 10 sessions across four weeks. Both sides showed significant reductions in wrinkle volume around the eyes (31.6% for red and 29.9% for amber). However, the authors reported that "none of the treatments improved skin hydration and viscoelasticity."³ Because the trial compared two wavelengths rather than an untreated or sham control, it does not show how results compare with no treatment.

What systematic reviews conclude

A 2018 systematic review of 31 randomized controlled trials of LED devices in dermatology assigned skin rejuvenation (photoaging and wrinkles) a grade C recommendation — a lower level of evidence than it assigned to acne or wound healing. The reviewers noted high variability in treatment parameters and said it was difficult to identify an optimal dose.⁴

A 2023 meta-analysis of LED studies across skin conditions reported effectiveness for skin rejuvenation, among other uses, and concluded that LEDs "could be potential candidates for future cosmetic applications."⁵

A 2023 systematic review focused on the oncologic safety of red and near-infrared light for aesthetic skin rejuvenation concluded that current evidence suggests it is oncologically safe for that purpose. The same review noted that most clinical evidence comes from methodologically flawed, single-center trials and case series, and that no large multicenter randomized trials exist.⁶

In January 2026, Santé.fr, the French government's public health information service, published a review of the evidence on LED masks. It described the reported improvements in wrinkles and collagen as moderate, noted that experts lack the data to define an optimal protocol, and stated that the durability of effects and potential long-term side effects are unknown.⁷

Limitations of the current evidence

• Few large trials. Reviewers note the absence of large, multicenter randomized trials.⁶
• Different devices and settings. Studies used different wavelengths, doses, and schedules, which makes it hard to compare results or apply them to a particular consumer device.⁴
• Mixed outcomes. Some trials reported changes in wrinkles without changes in elasticity.³
• Short follow-up. Most studies followed participants for weeks to a few months, and the durability of any changes is not well established.^1,7
• Comparison groups. Not all studies included an untreated or sham control group.³

Summary

Several randomized trials have reported changes in wrinkle measurements, skin roughness, or collagen density after red or near-infrared light treatment, and one reported increased elasticity. Others found no change in elasticity. Systematic reviews rate the overall evidence for skin rejuvenation as limited, and the research does not measure "tightening" as a defined outcome. Larger, longer, well-controlled trials would be needed to draw firmer conclusions.

Disclaimer

This article is for general informational purposes only and does not constitute medical, legal, or professional advice. It summarizes published research and is not intended to diagnose, treat, cure, or prevent any condition, or to suggest that any device will produce a particular result. Study findings may not apply to any individual. Regulatory clearance of a device does not guarantee its effectiveness. Redlight Ratings is not a medical provider. Anyone with questions about skin aging or a skin condition should consult a qualified healthcare professional.

References

1. Lee SY, Park KH, Choi JW, et al. A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation. Journal of Photochemistry and Photobiology B. 2007;88(1):51-67. https://pubmed.ncbi.nlm.nih.gov/17566756/
2. 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;32(2):93-100. https://pubmed.ncbi.nlm.nih.gov/24286286/
3. Mota LR, Duarte IS, Galache TR, et al. Photobiomodulation reduces periocular wrinkle volume by 30%: A randomized controlled trial. Photobiomodulation, Photomedicine, and Laser Surgery. 2023;41(2):48-56. https://pubmed.ncbi.nlm.nih.gov/36780572/
4. Jagdeo J, Austin E, Mamalis A, Wong C, Ho D, Siegel DM. Light-emitting diodes in dermatology: A systematic review of randomized controlled trials. Lasers in Surgery and Medicine. 2018;50(6):613-628. https://pmc.ncbi.nlm.nih.gov/articles/PMC6099480/
5. Ngoc LTN, Moon JY, Lee YC. Utilization of light-emitting diodes for skin therapy: Systematic review and meta-analysis. Photodermatology, Photoimmunology & Photomedicine. 2023;39(4):303-317. https://pubmed.ncbi.nlm.nih.gov/36310510/
6. Glass GE. Photobiomodulation: A systematic review of the oncologic safety of low-level light therapy for aesthetic skin rejuvenation. Aesthetic Surgery Journal. 2023;43(5):NP357-NP371. https://pmc.ncbi.nlm.nih.gov/articles/PMC10309024/
7. Santé.fr (Service Public d'Information en Santé, France). Les masques à LED sont-ils efficaces et sûrs ? January 12, 2026. https://www.sante.fr/node/8069061