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SKIN & BEAUTYPEPTIDE PROFILE

Collagen Type III

Also known as Type III Collagen, Reticular Collagen, Fetal Collagen

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.

Last updated April 10, 2026

TL;DR

Quick summary

Collagen Type III is the second most abundant collagen, providing elasticity and flexibility to skin, blood vessels, and organs through reticular fibers. The ratio of Type I to Type III shifts with age, contributing to loss of skin softness and vascular compliance.

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Overview

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.

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Mechanism of action

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.

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Dosing protocols

PurposeRouteDosageFrequency
skin elasticity and vascular supportoral250010000 mgonce daily

Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.

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Research summary

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.[1][2][3]

📄This section cites 3 peer-reviewed sources. View all references →
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Evidence grading

Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.

strong
Contributes to skin elasticity and vascular integrityKuivaniemi 1997 biochem review and decades of basic-science characterization established tissue roles
moderate
Type I:III ratio shifts with agingHistological and biochemical studies in dermis and vasculature confirm age-related ratio shifts
preliminary
Supplementation improves skin outcomesNo Type III-specific RCTs; benefits extrapolated from mixed-collagen trials Proksch 2014, Asserin 2015
strong
COL3A1 mutations cause vascular Ehlers-DanlosWell-established human genetics; EDS type IV diagnosis based on COL3A1 sequencing

Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data

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Side effects

Generally well tolerated
Mild GI discomfort (high doses)
Rare source-specific allergies

Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.

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Common stacks

Peptides commonly paired with Collagen Type III for synergistic effects.

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Sourcing & access

Research compound

Collagen Type III is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).

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Frequently asked questions

Collagen Type III is the second most abundant collagen in the human body, found predominantly in skin, blood vessel walls, internal organs, and muscles. It forms thin, flexible reticular fibers co-expressed with Type I collagen throughout life. Mutations in the COL3A1 gene cause Ehlers-Danlos syndrome type IV, a connective tissue disorder characterized by fragile blood vessels and skin.

Type III collagen provides elasticity and flexibility through fine reticular fibers rather than the structural rigidity imparted by thick Type I collagen fibrils. It is proportionally higher in younger skin, contributing to the softness and suppleness characteristic of young dermis. The ratio of Type I to Type III collagen shifts with age, contributing to progressive loss of skin softness, vascular compliance, and tissue pliability.

Type III-specific clinical evidence is sparse. Most collagen supplement RCTs use mixed hydrolyzed collagen containing Types I and III together, making it difficult to attribute results to Type III specifically. The biological roles of Type III are well-established from basic science and human genetics. Supplement-specific claims for Type III alone are extrapolated from this biological knowledge rather than from Type III-specific clinical trials.

Collagen Type III is typically consumed as a component of mixed hydrolyzed collagen products at 2,500 to 10,000 mg once daily. Bovine hide and fish skin sources are particularly rich in Type III collagen. Single-type Type III supplements exist but are less common than mixed collagen products. It is often combined with Type I collagen to provide broad connective tissue support.

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Research references

  1. Type III collagen structure, biosynthesis, and tissue distributionKuivaniemi H, Tromp G, et al.Biochem J, 1997PubMed
  2. Collagen-derived peptides stimulate fibroblast collagen synthesis in vitroAsserin J, Lati E, et al.J Cosmet Dermatol, 2015PubMed
  3. Oral collagen peptide supplementation and skin aging biomarkersProksch E, Segger D, et al.Skin Pharmacol Physiol, 2014PubMed
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