Quick definition: Collagen is the most abundant protein in the human body and the main structural protein in skin. Made by cells called fibroblasts in the dermis, it forms strong, rope-like fibers that give skin firmness and support. Production slows with age, and sun exposure, smoking, and sugar speed up its breakdown, contributing to wrinkles and sagging.
What is collagen?
Collagen is a structural protein found throughout the body, in skin, bones, tendons, ligaments, and other connective tissues. Cleveland Clinic notes that it accounts for about 30% of the body's total protein.
"Collagen is the most abundant protein in your body." — Cleveland Clinic
At the molecular level, collagen is built from three protein chains wound into a triple helix. Those molecules then bundle into fibrils and fibers. According to the StatPearls chapter on collagen synthesis, at least 28 types of collagen have been identified, and type I alone makes up more than 90% of the collagen in the body. In the skin, types I and III dominate.
How collagen works in skin
In skin, collagen lives mainly in the dermis, the middle layer beneath the epidermis. There, fibroblasts produce collagen alongside elastin (which lets skin snap back) and water-binding molecules like hyaluronic acid. Together they form the scaffold that makes young skin feel firm and bouncy.
Making collagen takes raw materials. StatPearls explains that vitamin C is an essential cofactor for the enzymes that stabilize the collagen helix, which is why severe vitamin C deficiency (scurvy) causes fragile skin and poor wound healing. The Harvard T.H. Chan School of Public Health adds that zinc and amino acids from dietary protein are also needed.
Why collagen declines with age
Two things happen as we get older: the body makes less collagen, and the collagen it has breaks down faster. Harvard's Nutrition Source describes how collagen in the deeper skin layers shifts from a tightly organized network to a disorganized one over time.
Several factors accelerate the loss:
Sun exposure: Cleveland Clinic says too much sunlight both reduces collagen production and causes it to break down more quickly. This is the single biggest controllable factor.
Smoking: Damages collagen and elastin, contributing to wrinkles.
High sugar intake: Sugar forms advanced glycation end products (AGEs), which can make collagen stiff and brittle.
Lifestyle: Harvard also lists excess alcohol, lack of sleep, and lack of exercise.
How to increase collagen in your face: what the evidence says
There is no single fix, but several approaches have real evidence behind them, or at least a sensible rationale:
Wear sunscreen every day. Protecting existing collagen from UV breakdown is the most reliable strategy.
Use a retinoid. Topical retinoids (retinol, or prescription tretinoin) are among the most studied ingredients for photoaged skin. Start slowly to avoid irritating your skin barrier.
Consider vitamin C. Because the body needs it for collagen synthesis, topical vitamin C serums are a popular addition to routines.
Eat enough protein and produce. A balanced diet provides the amino acids, vitamin C, and zinc your body uses to make collagen.
Don't smoke, and limit added sugar.
Professional treatments. Microneedling, radiofrequency, and certain laser procedures are designed to trigger a wound-healing response in the dermis.
What about collagen supplements? Harvard notes that some randomized controlled trials have found collagen supplements improve skin elasticity, but it also cautions:
"Most if not all of the research on collagen supplements are funded" — Harvard T.H. Chan School of Public Health
That sentence continues by noting the funding comes partly or fully from related industries. In other words, the early findings look promising but deserve cautious interpretation.
Red light therapy and collagen: what the research shows
Interest in red light therapy for collagen comes from a field called photobiomodulation (PBM): using low-level red and near-infrared light to influence cell activity.
Proposed mechanism: A 2024 review in the International Journal of Molecular Sciences explains that light is absorbed by photoreceptors in cells, including cytochrome c oxidase in mitochondria, which may affect energy production. The authors write that PBM's use in skin rejuvenation is based on an apparent remodeling effect involving type I and type III collagen and elastin.
Clinical data: A controlled trial by Wunsch and Matuschka in Photomedicine and Laser Surgery enrolled 136 volunteers who received 30 twice-weekly sessions of either red light (611–650nm) or broadband light (570–850nm). Compared with controls, the treated groups showed improvements in skin complexion, skin feeling, and roughness, and an increase in collagen density measured by ultrasound.
Limitations: The same 2024 review notes that standardized protocols across skin types and conditions are still lacking. Results depend heavily on wavelength, dose (fluence), and treatment schedule, so findings from one study don't automatically apply to a different device or setting.
Collagen in beauty and personal care
Collagen shows up across the beauty industry in several forms:
Topical collagen creams: Collagen molecules are generally too large to penetrate the skin barrier, so these act mostly as moisturizers on the surface.
Ingestible collagen: Powders and drinks made from hydrolyzed collagen peptides, with the evidence caveats noted above.
In-office treatments: Energy-based and injectable procedures aimed at the dermis.
At-home light devices: Red and near-infrared LED devices, inspired by photobiomodulation research, used as part of a regular routine.
How Reseen fits in
Glow is a handheld facial wand with VIPE™ precision light at 660nm red and invisible 1064nm near-infrared, plus 460nm blue, combined with steady 108°F warmth, an EMS mode, and a gua sha-inspired glide. It is designed for 5-minute sessions, 3 to 5 times a week, to help skin look firmer and more radiant and to soften the look of fine lines.
Glow is a cosmetic device, and the research above describes study results, not claims about Glow. For the best-looking results, pair it with daily sunscreen and a consistent routine.
Frequently asked questions
What is collagen, in simple terms?
Collagen is the body's main structural protein. In skin, it forms a network of fibers in the dermis that provides strength and firmness. The body makes less of it with age, which contributes to wrinkles and sagging.
What destroys collagen in the face?
Sun exposure is the biggest factor, followed by smoking, high sugar intake, and natural aging. Excess alcohol and poor sleep may also contribute. Daily sunscreen is the most practical way to protect the collagen you have.
Does red light therapy increase collagen?
Some studies suggest it may. A controlled trial published in Photomedicine and Laser Surgery reported increased collagen density with red and broadband light, and reviews describe a plausible cellular mechanism. However, protocols vary widely and more standardized research is needed.
Do collagen supplements work for skin?
Some randomized trials have reported improvements in skin elasticity, but Harvard's Nutrition Source notes that most of this research is industry-funded. If you try them, keep expectations modest and prioritize sunscreen and a balanced diet.
Browse every term in the Reseen glossary.
Sources
Collagen: What It Is, Types, Function & Benefits — Cleveland Clinic
Biochemistry, Collagen Synthesis — Rahimi N, Launico MV; StatPearls, NCBI Bookshelf, updated 2026
Collagen — The Nutrition Source, Harvard T.H. Chan School of Public Health
Unlocking the Power of Light on the Skin: A Comprehensive Review on Photobiomodulation — Hernández-Bule ML, et al.; International Journal of Molecular Sciences, 2024
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 — Wunsch A, Matuschka K; Photomedicine and Laser Surgery, 2013
This article is for general education and is not medical advice. Reseen devices are cosmetic devices and are not intended to diagnose, treat, cure, or prevent any disease. If you have a skin or scalp condition, talk to a board-certified dermatologist.