Collagen

Collagen is the main structural protein in the skin—the scaffolding that gives it firmness, strength and a smooth, plump surface. Produced by cells called fibroblasts, it makes up the large majority of the skin’s deeper layer, the dermis. From our mid-twenties onward the body gradually makes less of it while existing collagen breaks down faster, which is why supporting and stimulating collagen sits at the heart of so much skincare and medical aesthetics.

At a glance

• What it is: The main structural protein of the skin, giving it firmness and strength
• Where it is: Mainly the dermis, where type I collagen makes up roughly 80–85% of the matrix
• Made by: Fibroblasts, the skin’s collagen-producing cells
• Why it declines: Chronological aging and UV exposure, which speed its breakdown by enzymes (MMPs)
• In aesthetics: Many treatments aim to stimulate new collagen (neocollagenesis)
• Supplements: Oral collagen peptides show some benefit for skin hydration and elasticity, with caveats

What is collagen?

Collagen is the principal protein of the dermis, where type I collagen is the most abundant form—accounting for roughly 80–85% of the dermal matrix—alongside type III.^[1][2] It is produced by fibroblasts, the main cells of the dermis, which also make elastin and the rest of the supporting matrix.^[2] Together, collagen provides tensile strength while elastin provides stretch and recoil—the combination that keeps skin firm, resilient and smooth.

Why collagen matters for skin

Think of collagen as the skin’s internal architecture. It forms the framework that holds everything in place, anchors the outer layer and gives the face its structure and cushioning.^[2] When collagen is plentiful and well-organised, skin looks firm and plump; as it thins and fragments, the surface loses support, and fine lines, wrinkles and laxity begin to show. This is why collagen is such a central theme in anti-aging skincare and aesthetic treatment.

Why collagen declines with age

Collagen loss has two main drivers. The first is chronological aging: collagen synthesis naturally slows over time. The second is sun exposure—ultraviolet light accelerates the breakdown of collagen, a process called photoaging, largely by activating enzymes known as matrix metalloproteinases (chiefly MMP-1) that digest type I collagen.^[1] The result is a progressive thinning of the dermis, with wrinkles and reduced elasticity. Because UV is such a major factor, daily sun protection is one of the most effective ways to preserve the collagen you have.

How aesthetic treatments stimulate collagen

Many aesthetic treatments work by prompting the skin to build fresh collagen—a process called neocollagenesis. Controlled micro-injury treatments such as microneedling and radiofrequency microneedling, along with certain lasers, trigger the skin’s repair response and new collagen formation. Biostimulatory injectables such as poly-L-lactic acid and calcium hydroxylapatite work more gradually, encouraging the skin to lay down its own collagen over months.^[1] Topical retinoids and vitamin C are also well known for supporting collagen. The common thread is that these treatments do not simply add volume—they help the skin rebuild its own scaffolding.

Do collagen supplements work?

Oral collagen has become popular, and the evidence is cautiously encouraging. A systematic review and meta-analysis found that collagen supplements, at doses of about 1–10 g per day, were associated with measurable improvements in skin hydration and elasticity compared with placebo.^[3] The caveats matter, though: the studies varied in quality and design, most involved women, and results should be read with some caution.^[3] It’s also worth understanding bioavailability—swallowed collagen is broken down into smaller peptides and amino acids during digestion rather than travelling intact to the skin—so a supplement supports the body’s raw materials rather than delivering collagen directly to the dermis.

Supporting and protecting your collagen

The most reliable strategy combines protection and stimulation: daily broad-spectrum sun protection to slow breakdown, evidence-based topicals such as retinoids and vitamin C, and, where appropriate, in-clinic collagen-stimulating treatments tailored to your skin. A personalised plan is more effective than any single product. To see how collagen-supporting treatments and skincare can be combined, explore Revel’s skin rituals.

Related glossary terms

• Fibroblasts
• Elastin
• Neocollagenesis
• Poly-L-Lactic Acid
• Calcium Hydroxylapatite
• Microneedling
• Bioavailability
• Revel Rituals of Renewal: Skin

Clinical & editorial sources

1. Bar O, Valiukevičienė S. Skin Aging and Type I Collagen: A Systematic Review of Interventions with Potential Collagen-Related Effects. Cosmetics. 2025;12(4):129. doi:10.3390/cosmetics12040129
2. Brown TM, Krishnamurthy K. Histology, Dermis. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 2022 Nov 14. NBK535346
3. Danessa G, Notario D, Regina R. Effects of collagen-based supplements on skin’s hydration and elasticity: A systematic review and meta-analysis. Indian J Dermatol Venereol Leprol. 2025. doi:10.25259/IJDVL_1165_2023