"Types I & III." "Type II for joints." "Multi-collagen with five types." Collagen labels love numbers. Here's what those types actually are, where they live in your body, and how much they should matter when you're choosing a supplement.
Written by Vita Globe Editorial Team | Reviewed against peer-reviewed reviews and randomized controlled trials
What's the difference between collagen types 1, 2 and 3?
They're three members of a family of 28 collagen types[1]. Type I is the main collagen in skin, bone and tendon; type II is the main collagen in cartilage; type III sits alongside type I in skin and blood vessels[1]. In supplements, most hydrolyzed collagen is rich in type I, while undenatured type II is a different kind of product studied for joints at milligram doses[3].
Caveat: Once collagen is hydrolyzed into peptides, its original structure is gone, so the "type" mainly tells you the source tissue.
Sources: Ricard-Blum 2011 · León-López 2019 · Lugo 2016 RCT · Verified 2026-09-27
In this article
How many types of collagen are there?
Researchers have identified 28 collagen types in vertebrates, numbered with Roman numerals in the order they were discovered[1]. They share the signature triple-helix structure but differ in their chains, how they assemble and where they're found. Some form long fibers that give tissues tensile strength; others form sheets, networks or connections between tissues[1].
For supplements, only a few types come up: I, II and III, and sometimes V and X in "multi-collagen" blends. The table below covers the three that matter most.
| Type | Where it's mainly found | How it shows up in supplements |
|---|---|---|
| Type I | Skin, bone, tendon, ligaments | Most hydrolyzed collagen peptides (bovine, marine, porcine) |
| Type II | Cartilage | Undenatured type II (milligram doses) or hydrolyzed cartilage collagen |
| Type III | Skin, blood vessels, alongside type I | Often listed with type I in bovine collagen |
What are type I and type III collagen?
Type I is the classic fiber-forming collagen and the one most people mean when they say "collagen." It gives skin its strength and forms the scaffolding of bone and tendon[1]. Type III is also fiber-forming and is typically found in the same tissues as type I, including skin and blood vessel walls[1].
Because both live in skin and hide, collagen made from animal skins naturally contains a mix. That's why bovine collagen is often labeled "types I & III." Marine collagen from fish skin is generally described as rich in type I[2].
Most skin research used hydrolyzed collagen of this kind. For example, one well-known trial gave women 2.5 g or 5 g of collagen peptides daily for eight weeks and found improved skin elasticity compared with placebo[5].
What is type II collagen?
Type II collagen is the main collagen of cartilage, the smooth tissue that cushions joints[1]. It appears in supplements in two quite different forms:
- Undenatured type II collagen keeps its native structure and is taken in small, milligram-level doses. It's thought to work through the immune system in the gut rather than as building material. In a randomized, placebo-controlled trial of 191 people with knee osteoarthritis, 40 mg a day for 180 days reduced overall WOMAC symptom scores more than placebo[3].
- Hydrolyzed collagen for joints is taken in gram amounts, like skin collagen. A 2019 meta-analysis of randomized, placebo-controlled trials found collagen improved total WOMAC scores and pain on a visual analog scale in people with osteoarthritis[4].
So "type II" on a label doesn't tell you much by itself: check whether it's undenatured or hydrolyzed, and at what dose. For the full joint picture, read Collagen for Joints: What the Research Shows.
Does the collagen type on a label matter?
Less than marketing suggests, at least for hydrolyzed collagen. Hydrolysis cuts collagen into small peptides of roughly 3–6 kDa[2]. At that point it no longer has the triple-helix structure that defines a type. What's left is a mix of peptides whose amino acid makeup reflects the source. Your body then breaks those down further and builds its own collagen types where it needs them.
That's why "multi-collagen" blends with five types aren't automatically better. We found no strong evidence that combining several hydrolyzed types improves results over a single well-dosed hydrolyzed collagen. Dose, form (hydrolyzed vs. undenatured) and consistency matter more.
The honest summary
- Type I: skin, bone, tendon. Most collagen peptides.
- Type II: cartilage. Undenatured type II is a separate, milligram-dose product.
- Type III: skin and blood vessels, usually alongside type I.
- For hydrolyzed collagen, dose and consistency matter more than the type number.
Which type should you choose?
If your interest is skin, hair and nails, a hydrolyzed collagen (typically type I-rich) matches what most beauty research used. If your interest is joints, both undenatured type II and hydrolyzed collagen have trial data, but at very different doses, so read labels carefully and talk to your healthcare provider, especially if you have a joint condition.
Whatever you choose, check the source. Collagen is always animal-derived, so it isn't vegan, and marine collagen comes from fish. See What Is Hydrolyzed Collagen? for more on sources, or Best Collagen for Women Over 40 for a label checklist.
Our option
Vita Globe Hydrolyzed Collagen Gummies – 60ct
A simple hydrolyzed collagen peptide gummy for a hair, skin and nails routine, with a suggested use of 2 gummies once daily, preferably with a meal. Every Vita Globe product is tested by an independent third-party lab. See the Supplement Facts panel for the collagen amount and source.
Frequently asked questions
Which type of collagen is best for skin?
Most skin trials used hydrolyzed collagen peptides, which are typically rich in type I[5].
Can you take type 1 and type 2 collagen together?
There's no known reason you can't, but they're usually different products at very different doses. Ask your healthcare provider if you're combining supplements.
Is type 2 collagen good for joints?
One randomized trial found 40 mg a day of undenatured type II collagen improved knee osteoarthritis symptom scores versus placebo over 180 days[3]. More independent research would help.
Is marine collagen type 1?
Marine collagen from fish skin is generally described as type I-rich[2]. Check the label for specifics.
Is multi-collagen better than single-type collagen?
We found no strong evidence that it is. Dose and form matter more.
Sources
- Ricard-Blum S. The collagen family. Cold Spring Harb Perspect Biol. 2011;3(1):a004978. doi:10.1101/cshperspect.a004978
- León-López A, Morales-Peñaloza A, Martínez-Juárez VM, Vargas-Torres A, Zeugolis DI, Aguirre-Álvarez G. Hydrolyzed collagen—sources and applications. Molecules. 2019;24(22):4031. doi:10.3390/molecules24224031
- Lugo JP, Saiyed ZM, Lane NE. Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study. Nutr J. 2016;15:14. doi:10.1186/s12937-016-0130-8
- García-Coronado JM, Martínez-Olvera L, Elizondo-Omaña RE, et al. Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials. Int Orthop. 2019;43(3):531-538. doi:10.1007/s00264-018-4211-5
- Proksch E, Segger D, Degwert J, Schunck M, Zague V, Oesser S. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacol Physiol. 2014;27(1):47-55. doi:10.1159/000351376
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content, working from peer-reviewed research, systematic reviews and guidance from bodies such as the NIH and the FDA. We cite our sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or caring for a child.
