Collagen production peaks in your early twenties. After that, it declines at roughly 1% per year — a slow, compounding process that eventually shows up as fine lines, sagging, and thinner skin. By 50, you've lost about a quarter of the collagen you had at 25.
Red light therapy claims to reverse this. But unlike most skincare claims, this one has clinical trial data behind it.

Red light at wavelengths between 630–660nm and near-infrared light at 810–850nm penetrate the skin and are absorbed by mitochondria in dermal fibroblasts — the cells responsible for producing collagen and elastin.
This triggers a process called photobiomodulation: increased ATP production, nitric oxide release, and activation of cellular pathways that upregulate collagen synthesis (Hamblin, 2017). A 2019 study published in the Journal of the American Academy of Dermatology confirmed that low-level red and infrared light significantly increased expression of collagen, elastin, and hyaluronic acid in human skin (JAAD, 2019).
As Dr. Zakia Rahman at Stanford explains, the vasodilation caused by red light is likely the mechanism for wrinkle reduction — widened blood vessels deliver more nutrients to the dermis, supporting the ongoing repair and renewal process.

The most-cited study in the field is the Wunsch & Matuschka RCT (2014). 76 participants received treatment with either 633nm red light, a combination of 633nm and 830nm near-infrared light, or placebo. Treatment lasted 30 weeks.
Results: Both treatment groups showed significant improvements compared to control. Blinded clinical evaluation of photographs confirmed visible improvements. The researchers measured intradermal collagen density increase via ultrasound and found meaningful gains in the treatment groups (Wunsch & Matuschka, 2014).
Specific findings: 91% of participants in the treatment group reported improved skin tone. 87% reported reduction in fine lines. These were confirmed by blinded evaluators reviewing photographs — not just self-assessment (BiohackingTested, 2026).
A 2025 review of LLLT for skin rejuvenation further validated these findings, noting that red and near-infrared wavelengths consistently stimulate collagen synthesis and improve skin texture across multiple studies, though optimal treatment protocols still vary (SCIRP, 2025).

A systematic review specifically examining the oncologic safety of photobiomodulation for skin rejuvenation found no evidence linking PBM to cancer risk. Within established parameters, red and near-infrared light enhances proliferation of healthy cells without promoting neoplastic cell growth. The review concluded that PBM is oncologically safe for skin rejuvenation (PMC, 2023).
The Cleveland Clinic classifies red light therapy as safe and non-invasive, noting it uses non-UV, non-thermal light with no known serious side effects when used as directed.