Collagen types explained: which one is best for you?
Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy
The difference between collagen types I, II and III, marine vs bovine, and which suits skin versus joints.
Key takeaways
- Types I and III suit skin and structure; Type II (often UC-II) is the joint collagen.
- Marine collagen is mostly Type I; bovine supplies I and III; chicken provides Type II.
- Skin peptides are dosed at ~2.5–10 g/day; tiny UC-II doses work by a different mechanism.
What collagen is
Collagen is the main structural protein in skin, bones, tendons and cartilage, and it declines naturally with age. Supplements provide it as hydrolysed peptides — collagen broken into smaller, absorbable fragments. But 'collagen' isn't one single thing: there are several types, and products are sourced from different animals, which is why the labels can be confusing and why matching the type to your goal matters.
The main collagen types
Three types dominate supplements. Type I is the most abundant in the body and is the key one for skin, hair, nails, bones and tendons. Type III often occurs alongside Type I in skin and blood vessels. Type II is the collagen found in cartilage, so it's the one associated with joint products. In short: Types I and III lean toward skin and structure, Type II toward joints.
Sources: marine, bovine, chicken
The source determines the type. Marine collagen (from fish) is mostly Type I and popular for skin. Bovine collagen (from cattle) supplies Types I and III. Chicken collagen is a common source of Type II for joints. There's also egg-shell-membrane collagen. None is universally 'best' — the right choice depends on whether you're targeting skin or joints, plus dietary preferences.
Hydrolysed peptides versus undenatured Type II
A useful distinction for joints: most skin products use hydrolysed (broken-down) collagen peptides at multi-gram doses. Some joint products instead use 'undenatured' Type II collagen (often labelled UC-II) at a tiny dose, which is thought to work through a different, immune-related mechanism rather than as a building block. So a small Type II dose isn't necessarily under-dosing — it's a different approach with its own (still limited) evidence.
Dose, vitamin C and what to expect
For skin, trials generally use hydrolysed peptides at roughly 2.5–10 g/day, taken consistently for weeks to months, so a sub-gram sprinkle is unlikely to do much. Vitamin C is a genuine cofactor for the body's own collagen synthesis and is often paired with it. Realistic expectations matter: modest improvements in skin or joint comfort for some people, not a dramatic transformation.
How to choose
Match the type to the goal: Type I (and III) from marine or bovine sources for skin, hair and nails; Type II (often UC-II) for joints. Check the dose against the studied range for the form, look for added vitamin C for skin formulas, and remember collagen is animal-derived, so vegans need a different approach. As always, a transparent label beats an impressive-sounding but vague one.
Related guides
Collagen (Hydrolysed Peptides)
IngredientVitamin C
Skin & Anti-AgingSouth Beach Collagen Filler Serum
Frequently asked questions
Which collagen type is best for skin?
Type I (with some Type III), commonly from marine or bovine sources, as hydrolysed peptides.
Which collagen is best for joints?
Type II — often as undenatured UC-II at a small dose, which works through a different mechanism than skin peptides.
Is marine or bovine collagen better?
Marine is mostly Type I (skin-focused); bovine supplies Types I and III. Choose by goal and dietary preference.
How much collagen should I take for skin?
Skin trials generally use hydrolysed peptides at about 2.5–10 g/day, consistently for weeks to months.
This article is general information, not medical advice. See our medical disclaimer, and talk to a qualified healthcare professional about your own situation.