Collagen peptides explained: types, dose and how they work
Collagen peptides explained: types, dose and how they work
Collagen peptides are one of the most-searched supplement terms in the UK, and one of the most poorly explained. Most blog posts about collagen peptides skip past the actual biology and jump straight to product. Here is a clear, practical explainer of what collagen peptides actually are, how hydrolysis works, the five types of collagen and which ones matter, the dose backed by clinical trials, and how to think about marine versus bovine peptides.
What are collagen peptides?
Collagen peptides (sometimes called hydrolysed collagen, collagen hydrolysate or collagen hydrolysed peptides) are short chains of amino acids derived from native collagen protein that has been broken down through a process called hydrolysis. Native collagen is a long, tightly wound triple-helix protein that the human gut struggles to absorb. Hydrolysis uses heat, water and enzymes to break the long protein chains into much shorter di-peptides and tri-peptides, typically 2 to 5 kilodaltons in molecular weight, which the small intestine absorbs intact. Once absorbed, those short peptides circulate in the bloodstream and signal fibroblasts (the cells that make collagen and elastin) to upregulate synthesis. They also raise blood levels of the three amino acids that dominate collagen structure: glycine, proline and hydroxyproline. The clinical evidence base for hydrolysed collagen peptides on skin elasticity, hydration, joint comfort and dermal density is moderate-to-strong when daily clinical doses are taken consistently for 8 to 12 weeks.
The five types of collagen and which ones matter
Type I, II and III, the supplements that count
There are at least 28 types of collagen in the human body, but five matter for supplementation. Type I makes up around 90% of human collagen and dominates skin, bone, tendons and dentin. Type II is the dominant collagen in cartilage and the joints. Type III often appears alongside type I in skin, blood vessels and internal organs. Type I plus type III is the typical skin-and-tendon profile, type II is the cartilage profile. Most marine collagen peptides are predominantly type I and type III. Bovine peptides cover type I, II and III depending on source. Our companion piece on hydrolysed collagen vs marine collagen unpacks the source vs processing distinction.
How collagen peptides work in the body
After ingestion, hydrolysed collagen peptides are absorbed across the intestinal wall as small di- and tri-peptides, with hydroxyproline-containing peptides like Pro-Hyp and Hyp-Gly detectable in the bloodstream within an hour of dosing. These circulating peptides act in two ways: they raise the amino acid pool the body uses to build new collagen, and they appear to act as signalling molecules that upregulate fibroblast collagen and hyaluronic acid synthesis. The complete UK guide to liquid marine collagen covers the absorption picture in more depth.
Marine versus bovine peptides
Marine collagen peptides come from fish skins and scales, are predominantly type I, and tend to have smaller peptide sizes than bovine, which may aid absorption. Bovine peptides come from cattle and cover types I, II and III depending on source. For skin-focused outcomes, marine is the typical preferred source. For joint and cartilage support, type II bovine or chicken-sourced peptides have specific evidence. Browse the Kollo collagen powder collection for marine-based options.
Collagen types compared at a glance
| Type | Where in body | Common source | Best for |
|---|---|---|---|
| Type I | Skin, bone, tendons, dentin | Marine, bovine | Skin elasticity, hair, nails |
| Type II | Cartilage, joints | Chicken, bovine | Joint comfort, cartilage |
| Type III | Skin (with type I), blood vessels | Marine, bovine | Skin firmness, vascular tissue |
| Types IV and V | Basement membranes, hair, placenta | Rarely supplemented | Specialist applications |
How to take collagen peptides for results
- Take 10g of hydrolysed collagen peptides daily, the practical clinical floor for skin and joints
- Pair with vitamin C, the cofactor for collagen synthesis
- Choose a named peptide source like Naticol with published clinical trials
- Confirm Informed Sport or equivalent third-party purity testing
- Prioritise daily consistency, splitting doses across the day adds no benefit
- Allow 8 to 12 weeks of consistent daily intake before judging visible results
Collagen peptides are not magic, but the clinical evidence for hydrolysed marine peptides on skin elasticity, hydration and joint comfort is solid when the dose, peptide source and consistency are right. Browse the Kollo collagen powder collection for products built around clinical-dose Naticol marine collagen peptides plus vitamin C, biotin and B-complex, all registered with Informed Sport.
Kollo Health was co-founded by Jenni Falconer - TV presenter, Smooth Radio breakfast host, ten-time London Marathon runner and host of the RunPod podcast.
