Type I vs Type II vs Type III Collagen: What's the Difference?

Last updated: August 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy

Type I dominates skin, bone and tendon. Type III sits alongside it in skin and blood vessels. Type II is the collagen of cartilage, and it is the one used for joints — usually as undenatured UC-II at 40 mg rather than as grams of peptides.

What each type does

Type I is the most abundant collagen in the body — roughly 80–90% of skin collagen, plus bone, tendon and ligament. Type III is found with type I in skin, blood vessels and organs, and is more prominent in younger skin. Type II is the principal collagen of articular cartilage and is structurally distinct.

Matching source to goal

Skin, hair, nails and bone: type I and III, from bovine or marine collagen peptides at 2.5–10 g daily. Marine is almost entirely type I. Joints: type II, and here the form matters more than the type — undenatured UC-II at 40 mg works through oral tolerance, an immune mechanism, and must not be heated.

Why multi-type products are usually marketing

Products advertising five or ten collagen types sound comprehensive. In practice types I and III cover skin and connective tissue, and type II covers joints, and the effective doses for those two approaches differ by a factor of 250. A product mixing them rarely delivers a study dose of either.

Key ingredients to understand

The ingredients most relevant to this question, with what the evidence actually supports:

• Collagen Peptides — Hydrolysed collagen peptides have some of the better evidence in the supplement market for skin hydration and elasticity, and moderate evidence…
• Marine Collagen — Marine collagen comes from fish skin and scales, is predominantly type I — the type that dominates skin — and has smaller peptides that may…
• Collagen (Hydrolysed Peptides) — Collagen peptides are the most popular skin and joint supplement. There is some genuine trial evidence for modest improvements in skin hydration…
• Hyaluronic Acid — Hyaluronic acid is a gel-like molecule that holds water in skin and joints. Oral supplements are popular for skin hydration and anti-aging, and…

Frequently asked questions

Do I need all three types?

No. Pick based on your goal — I and III for skin, II for joints.

Can I take type I and type II together?

Yes, no conflict, but check each is at its own effective dose. Do not add UC-II to anything hot.

Is chicken collagen type II?

Chicken sternum is the usual source of UC-II, yes.

This article is general information, not medical advice. FactoWiki may earn a commission from links on product review pages (never on comparisons). Always check with a qualified healthcare professional about your own situation.