Type 1 collagen gives skin, bones, and tendons their strength; type 3 provides flexibility to blood vessels, muscles, and organs.
Collagen is the most plentiful protein in the human body, but it is not one single protein. It is a family, and two members dominate the conversation: type 1, the workhorse that builds tough structure, and type 3, the flexible strand that lets stretchy tissues spring back. Understanding what types 1 and 3 collagen are comes down to one trade-off: strength versus elasticity.
Most people meet these two types on a supplement label, not in a biology textbook. Before buying, it helps to know which body parts each one supports and why the two are almost always sold together.
Collagen Is A Family, Not One Protein
Researchers have identified 28 to 29 distinct collagen types, and all of them are structural proteins with different shapes and jobs. Type 1 collagen makes up about 90% of the collagen in your body, and it is the densely packed, thick-fiber version found in skin, bones, tendons, and ligaments.
Type 3 collagen is the thinner, more flexible counterpart. It shows up in muscles, blood vessels, and internal organs, where tissues need to stretch and recoil without tearing. In healing tissue, type 3 appears early, and type 1 gradually replaces it as the tissue matures — a pattern that shows how the two work as a team.
Type 1 vs. Type 3 Collagen: Where The Difference Shows
The practical distinction is simple: type 1 provides rigid tensile strength, and type 3 provides flexibility and support. Both are present in skin and connective tissue, where strength and elasticity have to coexist. Cleveland Clinic’s collagen overview groups type 1 with skin, bones, tendons, and ligaments, and type 3 with blood vessels and internal organs.
The table below summarizes the main differences at a glance.
| What’s Compared | Type 1 Collagen | Type 3 Collagen |
|---|---|---|
| Share of body collagen | About 90% | Much smaller share |
| Fiber structure | Dense, thick fibers | Thin, flexible fibers |
| Primary job | Tensile strength and structure | Elasticity and recoil |
| Main locations | Skin, bones, tendons, ligaments | Muscles, blood vessels, organs |
| Role in skin | Primary structural collagen of the dermis | Helps organize the matrix, adds elasticity |
| Role in healing | Replaces type 3 as tissue matures | Appears early in healing tissue |
| Stretchable organs | Minor presence | Prominent in uterus, intestines, lungs |
Because the two types often appear together, the strength-versus-flexibility split is really a division of labor. Structures like skin need both: type 1 gives the dermis its framework, and type 3 keeps that framework from becoming brittle.
Do Type 1 And 3 Collagen Supplements Work?
The honest answer: supplements can support normal structure, but research does not show they treat disease or reliably improve specific outcomes. The research on types 1 and 3 describes where these proteins live and what they do mechanically; it does not establish a medical treatment effect. A supplement can still be a reasonable choice for supporting normal structure, as long as you keep expectations realistic.
Most products labeled “type 1 and 3 collagen” use bovine collagen, because cow-derived collagen is naturally rich in both types. Products differ by source and type composition, so labels matter. People with dietary restrictions, allergies, or ingredient sensitivities should check the source material carefully before buying.
If you are comparing bottles, our roundup of the best collagen types 1 and 3 covers the label details worth checking before you buy.
Here is the practical takeaway: type 1 is the strength protein for skin, bones, and tendons, and type 3 is the flexibility protein for blood vessels, muscles, and organs. Most supplements pair them because the body uses both, often in the same tissues. Match your expectations to that reality: collagen supports normal structure, not miracle results.
FAQs
Is marine collagen type 1 or type 3?
Marine collagen is primarily type 1, since fish skin and scales are rich in the same structural collagen found in human skin and bones. Bovine collagen, by contrast, delivers a mix of types 1 and 3. If you specifically want both types in one product, check the source and the label’s type breakdown before choosing.
Can vegetarians take type 1 and 3 collagen?
Most type 1 and 3 collagen supplements are not vegetarian, because the collagen itself comes from animal tissue, typically bovine hide. Vegetarians and vegans usually look for collagen builders instead, such as vitamin C and amino acid supplements that support the body’s own collagen production.
Do you need both types of collagen?
Your body makes both types naturally and uses them in different tissues, so a supplement is not strictly necessary. A combined product makes sense if you want broad support for skin, bones, muscles, and blood vessels at once, which is why type 1 and type 3 so often share a label.
References & Sources
- Cleveland Clinic. “Collagen.” Explains what collagen is, the main types, and where each type is found in the body.