Collagen Type III

Collagen Type III is the second most abundant collagen in the body, found predominantly in skin, blood vessel walls, internal organs, and muscles. It forms thin, flexible reticular fibers and is almost always co-expressed with Type I collagen. In the dermis, Type III collagen contributes to skin elasticity and suppleness, particularly in younger skin where it is proportionally higher. In the vasculature, it provides elasticity and tensile integrity to arterial walls. Mutations in the COL3A1 gene cause Ehlers-Danlos syndrome type IV.

Type III collagen forms fine reticular fibers in the extracellular matrix that provide elasticity and flexibility rather than the rigidity imparted by Type I collagen fibrils. As a supplement (hydrolyzed), it delivers proline, glycine, and hydroxyproline residues that are incorporated into dermal ECM proteins. Supplemental collagen peptides derived from Type III-rich sources (such as bovine hide or fish skin) may preferentially support dermal elasticity and vascular collagen maintenance. The ratio of Type I to Type III collagen shifts with age, contributing to the loss of skin softness and vascular compliance.

The biological roles of Type III collagen are well-established from basic science. Supplement-specific research targeting Type III collagen is sparse compared to Types I and II — most collagen supplement RCTs use mixed hydrolyzed collagen containing all types. Observational and genetic evidence supports Type III collagen's role in skin youthfulness and vascular health. The lack of Type III-specific clinical trials limits specific evidence-based claims for supplementation.

Peptides commonly paired with Collagen Type III for synergistic effects.