Collagen

Collagen is the most abundant protein in the human body, forming the structural framework of the skin, tendons, joints, and bones - and red light therapy is among the best-documented non-pharmacological methods for stimulating its natural production.

Collagen is a fibrillar structural protein composed of a triple-helix structure of three polypeptide chains. It is the most abundant protein in the human body - making up approximately 30 percent of total body protein and 70 to 80 percent of the dry mass of the skin. It is primarily produced by fibroblasts - cells of the dermis - but also by chondrocytes in cartilage, osteoblasts in bone, and other connective tissue cells.

With age, collagen production naturally declines: after the age of 25, it decreases by 1 to 1.5 percent per year, gradually manifesting as thinning skin, wrinkle formation, reduced elasticity, and poorer joint regeneration. This is where photobiomodulation - red light therapy - comes into play, stimulating fibroblasts to increase collagen production without invasive procedures.

Types of collagen and where they act in the body

Scientists have identified more than 28 types of collagen. From the perspective of skin, joint, and musculoskeletal health, the most important are:

Collagen type I
The most widespread type in the body - accounting for 90 percent of total collagen. It is found in skin, tendons, ligaments, bones, and teeth. It is responsible for tissue strength and durability. Photobiomodulation primarily stimulates the production of type I collagen - red light (630 to 670 nm) increases the expression of the COL1A gene, leading to a histologically measurable increase in collagen fiber density in the dermis.

Collagen type II
The dominant collagen of cartilage - found mainly in articular cartilage, intervertebral discs, and the vitreous body of the eye. Its degradation is a key feature of osteoarthritis. NIR light (810 to 850 nm), with sufficient penetration depth, reaches joint cartilage and supports its regeneration.

Collagen type III
Also called reticular collagen - found in the skin, blood vessels, intestines, and internal organs. It works together with type I in forming the structural network of the dermis. The production of type III collagen is particularly important in wound healing.

Collagen types IV and V
Found in basement membranes and complex tissue structures. Their production is influenced by the overall condition of fibroblasts and the availability of ATP.

Red light and collagen: a scientifically documented mechanism

Photobiomodulation increases collagen production through multiple simultaneously acting mechanisms:

1. Activation of fibroblasts via mitochondria
Red light (630 to 760 nm) is absorbed by Cytochrome C oxidase (CCO) in fibroblasts. Increased production of ATP provides fibroblasts with the energy required for collagen synthesis and its secretion into the extracellular matrix. Fibroblasts exposed to red light show significantly increased density and metabolic activity, with abundant presence of collagen and elastin fibers in their surroundings.

2. Upregulation of collagen-related genes
Photobiomodulation increases the expression of COL1A (type I collagen) and TGF-β1 (transforming growth factor), which is a key signal for fibroblasts to initiate collagen synthesis. At the same time, it reduces the expression of matrix metalloproteinases (MMPs) - enzymes responsible for collagen degradation.

3. Reduction of oxidative stress
Oxidative stress is one of the main causes of premature collagen breakdown. Photobiomodulation restores redox balance in cells, thereby protecting existing collagen fibers from degradation by reactive oxygen species.

4. Release of growth factors
Red and NIR light stimulate the production of FGF2 (fibroblast growth factor), VEGF (vascular endothelial growth factor), and other signaling molecules that coordinate fibroblast proliferation and extracellular matrix remodeling.

Clinical results: what studies show

Collagen density and wrinkle reduction
A controlled clinical study (Wunsch and Matuschka) involving 136 volunteers documented, after 30 sessions of red and NIR light therapy, a statistically significant increase in dermal collagen density measured by high-frequency ultrasound (20 MHz). Dermatologists evaluating photographs using a blinded method reported improvement in skin texture and wrinkle reduction in 69 percent of cases. [R]

Periorbital wrinkle volume
A randomized controlled study documented a reduction in wrinkle volume around the eyes by 30 percent after 10 sessions of photobiomodulation (660 nm and 590 nm, 3.8 J/cm², 137 women aged 40 to 65). Measurements were performed using a VisioFace profilometric device.

Firmness and elasticity
A study reported an increase in fibroblast density and an improvement in skin elasticity by up to 72 percent after 150 days of red light therapy with an NIR component.

Meta-analysis of LED therapy
A systematic review and meta-analysis of 31 randomized controlled trials and case studies confirmed statistically significant wrinkle reduction and improvement in skin texture with LED therapy, with the red spectrum (630 to 660 nm) being the most consistently evaluated. [R]

Collagen and joints: beyond aesthetics

Collagen is not just about the skin. Articular cartilage is composed of 60 to 70 percent collagen, and it has no direct blood supply - nutrients and oxygen are delivered by diffusion from synovial fluid. This makes it highly sensitive to oxidative stress and inflammation.

NIR light (810 to 850 nm) penetrates deep enough to reach joint cartilage. Multiple clinical studies document reduced pain and improved joint function after photobiomodulation - partly through reducing inflammation, and partly by supporting the synthesis of cartilage collagen (type II) and protecting existing collagen fibers from enzymatic degradation.

In addition to cartilage, collagen is also essential for tendons, ligaments, and fascia, which are regularly exposed to mechanical stress. Supporting collagen synthesis through photobiomodulation is therefore relevant for athletes as well as for anyone engaged in active physical recovery.

Related terms

• Fibroblast - a dermal cell responsible for producing collagen, elastin, and hyaluronate; the primary target of photobiomodulation in skin rejuvenation
• Elastin - a protein working alongside collagen; provides skin elasticity and flexibility; its production is also stimulated by red light
• Extracellular matrix (ECM) - a network of proteins and polysaccharides filling the space between cells; collagen forms its main structural component
• TGF-β (transforming growth factor) - a key signal for initiating collagen synthesis in fibroblasts; photobiomodulation increases its expression
• MMP (matrix metalloproteinases) - enzymes that degrade collagen; photobiomodulation reduces their activity
• COL1A - gene for type I collagen; photobiomodulation increases its expression
• Photobiomodulation - therapy using red and NIR light to stimulate fibroblasts and collagen production
• ATP - cellular energy required for collagen synthesis; its production is increased by red light
• Oxidative stress - one of the main factors of collagen degradation; photobiomodulation reduces it
• Hyaluronate (hyaluronic acid) - a glycosaminoglycan working with collagen in hydration and structure of the dermis

Frequently asked questions about collagen

What is collagen and why is it important?

Collagen is the most abundant protein in the human body, making up approximately 30 percent of total body protein. It forms a strong structural network in the skin, joints, tendons, ligaments, and bones. In the skin, it accounts for 70 to 80 percent of dry mass and is responsible for strength, elasticity, and a youthful appearance. Without sufficient collagen, the skin loses elasticity, joints regenerate more slowly, and wounds heal less efficiently.

When does the body start losing collagen?

The natural decline in collagen production begins after the age of 25 and progresses at a rate of approximately 1 to 1.5 percent per year. After menopause, this decline accelerates significantly in women - in the first 5 years after menopause, the skin can lose up to 30 percent of its collagen. Accelerating factors include UV radiation, smoking, oxidative stress, excessive sugar intake (collagen glycation), and lack of sleep.

How does red light increase collagen production?

Red light (630 to 760 nm) is absorbed by Cytochrome C oxidase (CCO) in dermal fibroblasts. Increased CCO activity produces more ATP, providing fibroblasts with the energy needed for collagen synthesis. At the same time, light activates TGF-β signaling, increases expression of the COL1A gene, and reduces the activity of matrix metalloproteinases (MMPs) that degrade collagen. The result is an increase in dermal collagen density measurable by ultrasound after a series of sessions.

How many red light sessions are needed for visible collagen results?

Clinical studies typically use 8 to 30 sessions at a frequency of 2 to 5 times per week. Visible improvements in skin texture and wrinkle reduction are documented after 4 to 8 weeks of regular use. Increases in collagen density measured by ultrasound are observed after 30 sessions. Results depend on dose (J/cm²), wavelength, session frequency, and individual biological factors.

Is collagen in supplements as effective as stimulation with red light?

These are two different approaches with different mechanisms. Oral collagen (hydrolyzed) provides amino acids (glycine, proline, hydroxyproline) that can serve as building blocks for endogenous collagen synthesis. However, its absorption and bioavailability are still debated. Red light stimulates fibroblasts to produce collagen by activating cellular energy processes - it does not supply building blocks, but activates the biological process. Both approaches can complement each other and are not mutually exclusive.

Can red light also help with joint problems related to collagen?

Yes. NIR light (810 to 850 nm) penetrates deeply enough to reach joint cartilage composed of 60 to 70 percent collagen. Clinical studies document reduced pain in knee osteoarthritis, tendinopathies, and back pain. Mechanisms include reduction of inflammatory response, support of cartilage collagen synthesis (type II), and protection of existing collagen fibers from enzymatic degradation by metalloproteinases.

What is the difference between collagen and elastin?

Both are proteins of the dermal extracellular matrix, but they serve different functions. Collagen (primarily type I) provides strength and tensile resistance to tissues. Elastin provides elasticity and the ability to return to shape after deformation. In healthy skin, collagen and elastin work together. Photobiomodulation stimulates the production of both proteins - fibroblasts exposed to red light produce not only more collagen, but also more elastin.

Summary

Collagen is a fundamental structural protein that makes up about 30 percent of total body protein and 70 to 80 percent of the dry mass of the skin. Its production declines with age by 1 to 1.5 percent per year, leading to wrinkles, thinning skin, and reduced joint regeneration. Photobiomodulation with red light (630 to 760 nm) activates fibroblasts via Cytochrome C oxidase, increases ATP production, upregulates COL1A, and reduces the activity of collagen-degrading metalloproteinases. Clinical studies document a measurable increase in dermal collagen density and wrinkle reduction after a series of sessions.

Interested in skin care through photobiomodulation? Explore our Mitochondriak® devices, read how red light helps with skin, or visit the Better skin section.

Scientific studies and sources

• Wunsch A, Matuschka K. A controlled trial on red and NIR light: intradermal collagen density increase, wrinkle reduction, skin rejuvenation - 136 volunteers, 30 sessions, 69 % improvement evaluated by dermatologists. Photomed Laser Surg. 2014. PMC3926176
• Ngoc LTN et al. Utilization of LEDs for skin therapy - systematic review and meta-analysis of 31 RCTs, collagen, acne, wound healing. Photodermatol Photoimmunol Photomed. 2023. doi.org/10.1111/phpp.12841
• Reverse skin aging signs by red light PBM - mechanism of fibroblast, collagen, and elastin stimulation by 630 nm red light. Skin Research and Technology. 2023. PMC10311288
• Unlocking the Power of Light on the Skin - narrative review of PBM in dermatology, mechanism of collagen stimulation, TGF-β, COL1A. MDPI IJMS. 2024. doi.org/10.3390/ijms25084483