Clinical Evidence: Red Light Therapy for Scars

Red light therapy is increasingly discussed in skincare contexts, but the evidence base is uneven across different skin concerns. For scarring specifically, the clinical research is still developing compared to more established applications like photoageing or wound healing.

This post focuses on two randomised controlled trials that directly tested red and near-infrared LED therapy on post-surgical scars. Both are real, peer-reviewed studies with documented outcomes. We have also included a note on supporting laboratory research that provides biological context, with a clear label distinguishing lab work from clinical evidence.

Why Scars Are a Distinct Challenge

Scars form when the skin repairs itself after injury, surgery, or trauma. The process involves fibroblast activity and collagen remodelling. Hypertrophic scars (raised, firm, often red) occur when this process overproduces collagen. The goal of any scar intervention is to modulate this process - reducing excess collagen, softening the tissue, and improving the visual appearance over time.

Red and near-infrared light is thought to influence this through photobiomodulation - a process where light energy at specific wavelengths is absorbed by mitochondria in cells, triggering changes in cellular behaviour. In the context of scarring, this may include effects on fibroblast activity and inflammation. The two clinical trials below tested whether these effects translate into measurable outcomes in real patients.

Study 1: Kurtti and colleagues (2021)

Journal: Journal of Biophotonics

Design: Randomised controlled trial, split-face, dose-ranging, phase II

Wavelength: 633nm LED (red light)

Participants: 30 female patients following facelift surgery. Post-surgical periauricular (behind-the-ear) scars were used as the test site because facelift incisions produce bilateral, near-identical scars - one side treated, the other used as the control within the same patient.

Protocol: Patients received either a low dose (160 J/cm2) or medium dose (320 J/cm2) of 633nm LED therapy to one side of the face. The other side received no light treatment but underwent the same assessment process.

Results:

For scar induration (firmness/hardness, a key clinical marker):

Medium dose group: 77.8% reduction in induration on the treated side, compared to 50.0% on the control side
Low dose group: 62.5% reduction on the treated side, compared to 40.0% on the control side

Observer-rated scar assessment scores improved by 45.5% to 57.9% across the low and medium dose groups.

The split-face design is particularly valuable here. Because each patient serves as their own control, individual variation in healing rate is removed from the comparison. The treated side consistently showed greater improvement than the untreated side.

Wavelength relevance: 633nm is close to the 660nm red light output of the Lumovex Spectrum Pro Mask. The two wavelengths fall in the same red light window and share the same primary chromophores (light-absorbing molecules in tissue).

Study 2: Kim and colleagues (2022)

Journal: Lasers in Medical Science

Design: Randomised, double-blind, sham device-controlled clinical trial

Wavelength: 830nm LED (near-infrared)

Participants: 43 patients who had undergone thyroidectomy (a surgery that leaves a visible neck scar). 21 patients in the treatment group, 22 in the sham control group. Treatment began 1 week post-operation and continued for 4 weeks.

Results:

At 6 months follow-up:

The treatment group showed significantly higher patient satisfaction scores
Global Assessment Scale scores were significantly better in the treatment group
Pain scores (NRS - Numeric Rating Scale) were significantly lower in the treatment group
Vancouver Scar Scale (VSS) scores were significantly lower in the treatment group. The VSS measures vascularity, pigmentation, pliability, and height - a composite clinical picture of scar quality
Significant prevention of hypertrophic scar formation in the treatment group
No adverse effects were reported

The double-blind design means neither the patients nor the assessors knew who received real treatment versus the sham device. This eliminates both placebo response and assessor bias, making the findings more robust.

Wavelength relevance: 830nm near-infrared is close to the 850nm NIR output of the Lumovex Spectrum Pro Mask. The two wavelengths are within the same NIR absorption window and act through similar tissue penetration mechanisms.

Laboratory Research: Biological Plausibility

In addition to these clinical trials, Lev-Tov and colleagues (2013) published two in-vitro studies in Dermatologic Surgery examining the effects of red and infrared LED on human fibroblasts in a laboratory setting.

Important distinction: These are lab studies, not clinical trials. They did not involve patients or measure scar outcomes.

What they found was that both red and infrared LED reduced fibroblast proliferation without reducing cell viability. In plain terms, the cells survived but divided less aggressively. Since excess fibroblast activity is part of what drives hypertrophic (raised) scar formation, this provides a plausible biological mechanism for why light therapy might help - but it is not clinical proof.

We include this because understanding the mechanism behind a therapy is part of evaluating whether it is scientifically grounded. The Kurtti and Kim trials show clinical outcomes; the Lev-Tov work offers a window into why those outcomes might occur at a cellular level.

What the Evidence Shows - and Does Not Show

The two clinical trials above are genuine, peer-reviewed studies with positive findings. They show that red and near-infrared LED therapy can produce meaningful improvements in post-surgical scar outcomes under controlled conditions.

What the evidence does not show:

These are post-surgical scar studies. Generalising to old scars, acne scarring, or non-surgical injuries requires caution - those contexts have not been tested in the same way.
The total body of clinical scar research for red light therapy is smaller than for some other applications. Two positive trials are encouraging but not definitive.
Results vary between individuals. Scar tissue type, age of the scar, skin type, and consistency of use all influence outcomes.
These studies used clinical LED devices under controlled protocols. Home device results may differ.

Honest evaluation of evidence includes being clear about these limits. The studies we have cited are real, their findings are documented, and the wavelengths tested are directly relevant to the Lumovex device. That is where our confidence stops - we do not extrapolate beyond what the research actually shows.

Wavelength Coverage

One notable aspect of these two studies together is their wavelength range:

Kurtti (2021) used 633nm red light - directly relevant to the 660nm red channel
Kim (2022) used 830nm near-infrared - directly relevant to the 850nm NIR channel

The Lumovex Spectrum Pro Mask delivers both wavelengths simultaneously. These two studies suggest clinical activity at both ends of the spectrum for scar-related outcomes.

For targeted treatment of individual scars, the Lumovex Sculpt Wand allows precise application directly to the affected area. For scarring on the neck or jawline, the Spectrum Pro Mask + Neck Bundle extends treatment coverage beyond the face.

Educational Disclaimer

This post is for informational and educational purposes only. Red light therapy devices are not medical treatments and are not intended to diagnose, treat, cure, or prevent any medical condition. The studies cited describe outcomes in specific clinical settings with specific devices and protocols - these findings cannot be assumed to apply universally.

If you have concerns about scarring or wound healing, consult a qualified healthcare professional.

Clinical Evidence: Red Light Therapy for Scars - What 2 Clinical Trials Found