What Is Collagen and Why Is It So Important for the Body?
Collagen is the main structural protein in the human body, making up the largest proportion of all proteins. It is found in bones, muscles, skin, tendons, ligaments, and other connective tissues. Collagen forms a strong structural “framework” of the body—it is the substance that supports body structure and provides tissues with strength, elasticity, and resistance.
Collagen acts as a foundation upon which many bodily functions depend. Without it, tissues would lose their shape, joints would lose stability, and the skin would lose firmness.
Endogenous and Exogenous Collagen
Endogenous collagen is collagen that is naturally synthesized in the body. The body produces it on its own using amino acids, vitamins, and trace elements obtained from food. Endogenous collagen performs many vital functions, and its deficiency is associated with various health problems.
Exogenous collagen is collagen that the body does not produce itself. It is obtained from external sources, such as food or dietary supplements. Exogenous collagen is widely used in medicine and cosmetics, including for tissue repair, joint support, and improving the appearance of the skin.
Fast Facts About Collagen
Here are some key facts about collagen:
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Collagen is found throughout the human body, but especially in the skin, bones, and connective tissues.
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Some types of collagen fibers are stronger than steel when compared by equal weight.
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Collagen production naturally decreases with age and is negatively affected by smoking and UV radiation.
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Collagen is used in specialized wound dressings that help attract new skin cells to wound sites.
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Cosmetic products claiming to increase collagen levels in the skin usually cannot do so, because collagen molecules are too large to penetrate the skin.
What Is Collagen?
Collagen is a tough, insoluble, fibrous protein that makes up about one-third of all proteins in the human body. Collagen molecules bind tightly together to form long, thin fibrils that act as supportive structures and connect cells to one another. This is why collagen provides the skin with firmness, elasticity, and resistance to mechanical stress.
There are at least 16 different types of collagen, but approximately 80–90% of the collagen in the body consists of types I, II, and III. Each type has a different structure and function. Type I collagen fibrils are particularly strong and elastic—when compared by equal mass, they are stronger than steel.
What Is the Role of Collagen in the Body?
Collagen is produced by various cells, primarily connective tissue cells. It is found in the extracellular matrix, where it forms a complex network of macromolecules that determine the physical properties of tissues.
In the dermis—the middle layer of the skin—collagen forms a fibrous network in which fibroblasts operate. This network provides the foundation for the growth of new skin cells, skin renewal, and the repair of damaged tissue. Collagen also plays a role in replacing old, dead cells with new ones.
Some types of collagen act as protective barriers for internal organs, such as the kidneys.
Changes in Collagen With Age
As we age, the body naturally produces less collagen. As a result, the structural integrity of the skin weakens, wrinkles begin to form, skin elasticity decreases, and joint cartilage becomes more fragile.
After menopause, collagen synthesis in women decreases particularly sharply. Around the age of 60, a significant decline in collagen production is considered a normal part of the aging process.
In young skin, about 80% consists of type I collagen and around 15% of type III collagen. With age, natural collagen production decreases by approximately 1–1.5% per year. This process is associated with the formation of fine lines and deeper wrinkles. In addition, elastin fibers and hyaluronic acid—the main components of the extracellular matrix—undergo significant structural and functional changes.
What Does Science Say About the Effectiveness of Collagen?
In an open study involving 217 female volunteers, researchers evaluated the effects of a collagen-containing dietary supplement on visible signs of skin aging. The results were compared with aesthetic procedures such as botulinum toxin injections, laser treatments, or dermal fillers.
The study focused primarily on nasolabial folds, which deepen with age and are considered a reliable indicator of aging. A significant reduction in the depth of these folds was observed in 37% of participants. Interestingly, a similar improvement was noted regardless of whether the women had undergone surgical or aesthetic interventions. This confirms that collagen can be beneficial for improving skin condition.
Uses of Collagen in Medicine and Cosmetics
Collagen is resorbable, meaning it can be broken down, modified, and absorbed back into the body. It can be formed into compressed solid materials or gel-like lattice structures.
Due to its wide range of functions and natural origin, collagen is highly versatile and widely used in medicine. Medical-grade collagen can be derived from human, bovine, porcine, or ovine tissues.
Dermal Fillers
Collagen injections are used to shape skin contours, fill depressions, and reduce wrinkles. Collagen-based fillers can also help reduce scars, especially those without sharp edges. They are suitable for small-volume corrections, while larger defects are usually treated with fat, silicone, or implants.
Wound Care
Collagen dressings promote wound healing by attracting new skin cells to the damaged area. They are used to treat chronic, non-healing wounds, granulating wounds, necrotic wounds, second-degree burns, and donor skin sites.
Tissue Regeneration and Surgery
Collagen membranes are used in periodontal therapy, implantology, and oral surgery. They help regulate cell growth, accelerate healing, and are resorbable, meaning they do not require surgical removal after the procedure.
Osteoarthritis Treatment
Studies show that collagen supplements may help reduce pain and improve joint function in people with osteoarthritis. Absorbed collagen accumulates in cartilage and contributes to restoring its structure.
What Reduces Collagen Levels in the Body?
Collagen levels are significantly reduced by:
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high sugar intake (glycation processes),
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smoking,
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ultraviolet radiation from sunlight,
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autoimmune disorders,
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natural aging.
Avoiding these factors and maintaining a healthy lifestyle can help preserve collagen levels in the body for longer.
How Can Collagen Loss Be Prevented?
Collagen production is supported by:
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a healthy, balanced diet,
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adequate intake of vitamin C, vitamin A, copper, and amino acids,
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moderate sun exposure,
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not smoking,
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appropriate physical activity.
Hydrolyzed oral collagen, combined with vitamins, minerals, and antioxidants, may help improve skin elasticity and hydration, reduce wrinkles, and support nail and joint health.
