Collagen is EVERYWHERE. Literally. If you’ve explored any portion of the skin-care world, then you’re likely familiar with collagen, the amazing protein that deserves all of the hype that it receives. Understanding this dermal protein is imperative in understanding skin aging, so here is a basic breakdown on what it’s all about.

What is Collagen?

Collagen is the most abundant protein within the body. It is made up of a series of complex protein fibres arranged in long chains. Found in tendons, ligaments, blood vessels, corneas, teeth, and last but not least, skin and muscles. Within your skin, collagen fibres form a vast network in the dermal layers and are responsible for providing structural support and most of the skin’s density. As we age, collagen depletes which presents as loss of firmness, elasticity, strength of the skin and in turn fine lines and wrinkles.

Where is collagen found in the skin?

The dermis houses our essential connective tissues, like collagen, elastin, and reticulin. The Reticular Layer makes up the bulk of the dermis, acting as the primary support of the skin. It contains closely packed collagen resembling woven strands. Collagen makes up 10-30% of the weight of the dermis.

What is it made of?

Proteins are long chain amino acid structures, and collagen fibres are made up of many long chain protein fibres. Type I collagen, the most abundant form, has a long chain triple helix structure. Collagen is characterized by a triple-helical structure of three polypeptide chains with a characteristic amino acid sequence (Gly-X-Y) which is repeated frequently across the fibril structure, where Gly is glycine and X and Y would frequently be amino acids such as proline and hydroxyproline.

What are the types of collagen?

There are about 28 different forms of collagen found within the body. The Collagen family of proteins includes both fibril-forming and non-fibril-forming proteins, however the main collagens in the skin are the fibril-forming types, predominantly Type I and Type III. Type I collagen is present in skin, tendon, vasculature, organs and bone. Type II is predominantly present in cartilage. Type III is commonly found alongside Type I and usually represents about 15% of skin collagen. Collagen Type 1 is the strongest form of collagen, and Collagen Type 2 provides tensile strength to the tissue while Collagen Type 3 is inflexible. 

How does our collagen change over life phases?

Our bodies gradually produce less collagen as we age, beginning in early adulthood (around age 25) fibroblasts, aka the cells which produce collagen, become less active causing collagen production to decline by about 1.0%-1.5% a year. However, it decreases most quickly due to extrinsic aging factors such as sun exposure, smoking, excess alcohol, and lack of sleep and exercise. As our skin sustains cumulative exposure and damage, these factors damage collagen fibers and decrease in their ability to function correctly, reduce their thickness and strength, and lead to deep wrinkles and a loss of firmness.

Aged skin is characterized by dermal atrophy with reduced density of collagen fibres, elastin, and hyaluronic acid. In addition to reduced density, the collagen and elastin fibres in aged skin are found to be disorganized and abnormal compared to young and healthy skin. As we age and collagen levels decline, the collagen structure becomes more fragile and brittle leading to a weakening of the skin’s structural support. The proportion of the collagen types in our skin changes with age, younger skin contains about 80% type I collagen and about 15% collagen type III.

What cells create collagen?

Collagen is produced by cells called fibroblasts, which are a specialized cell found predominantly in the dermis. Fibroblasts are also responsible for the production of the protein elastin which gives skin the flexibility to stretch, and glycosaminoglycans (GAGs) which are part of the extracellular matrix and are pivotal for wound healing and moisture.These cells are essential to some of the work we do as estheticians, since many treatments are designed to create a controlled wound healing response in order to activate the production of new collagen fibres.

Wanna learn more about these amazing anti-aging treatments and the concept of CIT – Collagen Induction Therapy? Stay tuned for my next blog where I’ll dive deeper into collagen synthesis through treatments.

Xoxo, Kristen


Reilly DM,  Lozano J. Skin collagen through the lifestages: importance for skin health and beauty. Plast Aesthet Res 2021;8:2.

Ricard-Blum S. The collagen family. Cold Spring Harb Perspect Biol. 2011 Jan 1;3(1):a004978. doi: 10.1101/cshperspect.a004978. PMID: 21421911; PMCID: PMC3003457.

Wang F, Calderone K, Do TT, Smith NR, Helfrich YR, Johnson TRB, Kang S, Voorhees JJ, Fisher GJ. Severe disruption and disorganization of dermal collagen fibrils in early striae gravidarum. Br J Dermatol. 2018 Mar;178(3):749-760. doi: 10.1111/bjd.15895. Epub 2018 Feb 4. PMID: 28815554.

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