The five main types of collagen in the human body are Type I, Type II, Type III, Type IV, and Type V—each with a distinct role in skin, bones, joints, and organs.
Collagen is the most abundant protein in your body, forming the structural scaffold that holds tissues together. But not all collagen is the same. Your body produces at least 28 different types, yet five do the heavy lifting. Understanding which type does what helps you make smarter choices about supplements and what you’re actually putting into your body.
Type I Collagen: The Body’s Workhorse
Type I collagen accounts for about 90% of the collagen in your body, making it by far the most abundant. It provides structure to skin, bones, tendons, ligaments, teeth, blood vessels, and organs. Think of Type I as the steel framework of a building—it gives tensile strength and holds everything together. Most standard collagen supplements, especially those sourced from bovine hide or fish skin, are predominantly Type I.
Type II Collagen: Joint Support Specialist
Type II collagen is found primarily in elastic cartilage, the tough but flexible tissue that cushions your joints. Unlike Type I’s rope-like fibers, Type II forms a looser, more flexible network designed to absorb impact. This is why joint-focused supplements often highlight Type II collagen sourced from chicken sternum. It’s the type most directly linked to joint comfort and mobility.
What Are Type III, IV, and V Collagen?
Type III collagen appears in muscles, arteries, organs, and blood vessels—it often works alongside Type I to form reticular fibers that support soft tissues. Type IV collagen is unique because it forms sheet-like layers in the basement membrane of your skin and other tissues, acting as a filter between cell layers. Type V collagen is found in the cornea of your eyes, certain layers of skin, hair, and the placenta. While these three get less attention than Types I and II, they perform essential roles.
The 5 Main Collagen Types at a Glance
| Collagen Type | Primary Location | Key Function |
|---|---|---|
| Type I | Skin, bones, tendons, ligaments, teeth, blood vessels | Structural strength and framework for most tissues |
| Type II | Elastic cartilage | Joint cushioning and flexibility |
| Type III | Muscles, arteries, organs, blood vessels | Supports soft tissue structure alongside Type I |
| Type IV | Basal lamina / basement membrane of skin | Forms sheet-like structural layers and filters |
| Type V | Cornea, some skin layers, hair, placenta | Cell surface and tissue barrier functions |
The Truth About Collagen Supplements
The honest reality is that human research supporting these claims remains limited. The Cleveland Clinic notes that while some small studies show modest benefits, large-scale clinical trials are lacking. Your body breaks down ingested collagen into amino acids and peptides, then decides where to use them—it doesn’t simply send the Type II you swallowed straight to your knees. If you’re considering a supplement, look for products that include multiple collagen types with hydrolyzed (broken-down) peptides for better absorption. Before you buy, check out our picks for collagen pills that include all five types and see how they compare.
A common misconception is confusing the five main collagen types with the full list of 28 identified collagen types in humans. Types VI through XXVIII exist but are far less abundant and serve niche roles in things like the retina, bone mineralization, or developing tissues. For most people—and most supplement discussions—the five types above cover everything practical.
FAQs
Which collagen type is best for skin?
Type I collagen is the most abundant in skin and provides structural support. Most marine and bovine collagen supplements are primarily Type I, which is why they are commonly marketed for skin health.
Do I need all five types in one supplement?
Not necessarily. Most people’s needs are met by Type I for general structure and Type II for joint support. Supplements containing all five types are available but offer no confirmed advantage over targeted single-type products.
Are collagen supplements proven to work?
Evidence is mixed and generally limited. Some small studies suggest benefits for skin hydration and joint comfort, but large-scale independent clinical trials are lacking. Collagen supplements are not regulated like drugs by the FDA.
References & Sources
- Cleveland Clinic. “Collagen.” Overview of collagen types, functions, and supplement evidence.