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Which types of marine collagen exist, and where do they come from?

Pick up a handful of marine collagen products and read the backs. Most say marine collagen or fish collagen. A few say type I. Fewer still say which part of the fish the material came from, or how small the peptides are, although the powder inside was made to a precise specification on exactly those points.

Nothing in EU food law requires a supplement to declare the collagen type, the source tissue or the peptide size, so the distinction that matters most in this category, between collagen from fish skin and collagen from fish cartilage, is one you need to know how to look for. It is also the distinction we started from when we chose the collagen for Beauty Complete.

This article goes through the types, the sources and what the words on a label describe, and it explains why we chose Cartidyss®, a fish cartilage collagen from Abyss Ingredients, at the dose used in its human study. We have written separately about what collagen is and about how much collagen per day the studies used.

The short version

• Marine collagen is almost always type I from fish skin and scales, the by-product that exists in volume. Type II comes from cartilage and is a different material, because the cartilage's own glycosaminoglycans, chondroitin sulphate among them, come with it.

• No EU rule requires a label to state the collagen type, the source tissue or the peptide size. A named raw material with a published specification and a human study is the practical way to know what you are taking. In the only direct human comparison, hydrolysates at 2000 and 5000 Da gave closely comparable blood concentrations, so the peptide size matters less than the tissue and the study behind the material.

• Beauty Complete contains Cartidyss®, hydrolysed fish cartilage collagen from Abyss Ingredients in Brittany, at 500 mg per daily dose, the dose used in its placebo-controlled study on 46 women over 90 days, together with Hyabest® hyaluronic acid, Ceramosides™ phytoceramides, vitamin C, vitamin B2 and biotin.

Health Royals Beauty Complete, supplement with Cartidyss marine collagen, Hyabest hyaluronic acid, Ceramosides and vitamin C as PureWay-C

Which raw material, at which dose

Beauty Complete contains Cartidyss®, a hydrolysed type II collagen complex from fish cartilage made by Abyss Ingredients in Brittany: more than 65 percent collagen peptides, at least 95 percent of them under 3000 Da, and at least 25 percent chondroitin sulphate. The dose is 500 mg per daily dose, the same as in the raw material's published study, in which skin structure was measured by imaging. It sits alongside Hyabest® hyaluronic acid 120 mg, Ceramosides™ phytoceramides 30 mg, vitamin C 60 mg as PureWay-C, vitamin B2 1.4 mg and biotin 50 µg. The raw material is named so that it can be looked up.

See Beauty Complete, marine collagen and hyaluronic acid

What is marine collagen, and what is it made from?

Marine collagen is collagen extracted from fish, almost always from skin, scales or bones, and almost always type I.

EU hygiene law is plain about the raw material. Regulation 853/2004 defines collagen as the protein based product derived from animal bones, hides, skins and tendons. Every collagen supplement sold, marine or bovine, is made from the parts of an animal that the food industry does not sell as meat, which is also why collagen is a sensible use of material that would otherwise be thrown away.

A 2024 review in Collagen and Leather puts the scale of that stream at roughly 7.3 million tonnes of fish by-product discarded worldwide each year, with scales, bones, cartilage and skin routinely set aside during processing. Skin and scales dominate the collagen supply because they are the part of that stream that exists in volume and at low cost.

Fish cartilage is a far smaller stream, and it yields something structurally different. That smaller stream is where we went when we chose the collagen for Beauty Complete, and the next two sections explain why.

What is the difference between collagen type I, II and III?

Type I is the structural rope of skin, bone and tendon, type II is the framework of cartilage, and type III sits alongside type I in skin and in the walls of blood vessels.

Twenty eight collagen types have been described, and type I accounts for more than 90 percent of the collagen in the human body. It is not an exotic material. It is the default protein of connective tissue.

In skin specifically, a 2022 review in Biomedicines puts type I at roughly 80 to 85 percent of the dermal matrix and type III at roughly 8 to 11 percent. How those fibres are built, and what changes with age, is covered in our article on the biology of skin.

This is why so many products are sold as type 1 and 3 together. The pairing reflects real anatomy, but it is usually not two ingredients. Hide and skin contain both, so one extract carries both, and the label reports what came out of the process. Type 1 and 3 describes the raw material rather than a formulation decision.

Type II is the exception, because it comes from a tissue that is processed on a much smaller scale, and because it brings more than collagen with it.

Why is collagen type II not the same material as type I?

Because cartilage matrix is not made of collagen alone, so a cartilage extract is not made of collagen alone either.

Collagen makes up around two thirds of the dry mass of adult articular cartilage, and type II dominates that fraction, according to a review in Protein and Cell. Most of the rest is proteoglycan. Aggrecan carries chains of chondroitin sulphate and keratan sulphate, and as an NCBI Bookshelf chapter on aggrecan and hyaluronan explains, the high negative charge density of those glycosaminoglycans is what gives cartilage its water holding capacity and its resistance to compression.

Hydrolyse fish skin and you get peptides. Hydrolyse fish cartilage and the glycosaminoglycans come with the peptides, because they were never separate to begin with.

That shows up in a specification. Cartidyss®, the fish cartilage collagen in Beauty Complete, is described in its published study as more than 65 percent collagen peptides, at least 95 percent of them under 3000 Da, a minimum of 25 percent chondroitin sulphate and 9 percent minerals. A fish skin type I hydrolysate is close to pure peptide by comparison. The extra components make it a different material with a different research story, and that is what we looked at.

Cartidyss® is made by Abyss Ingredients in Brittany, a specialist manufacturer of marine raw materials with traceable sourcing and a published human study on its own material. Health Royals works with specialist manufacturers, researchers and supplier networks when raw materials are selected, and this is the kind of manufacturer we look for. In that study, randomised, double-blind and placebo-controlled and published in Molecules in 2021, 46 women aged 45 to 59 took 500 mg of the hydrolysed fish cartilage or placebo daily for 90 days, and the paper reported reduced wrinkle measurements and increased dermal thickness against placebo. Cartidyss® was studied at 500 mg per day. Beauty Complete contains 500 mg per daily dose. For us, the ingredient cannot be separated from its source, manufacturer and studied dose. Our ingredient guide on Cartidyss® goes through the study, its methods and the manufacturer in detail.

One thing to know about the words type II on a front label. Type II is sold in two different ways: hydrolysed, in hundreds of milligrams, as a source of peptides and glycosaminoglycans, or undenatured, at around 40 mg, where the proposed mechanism is immune tolerance in the gut rather than supply of material, as set out in a 2020 review in Animals. A pack that says only type II collagen could be either, and the dose tells you which. Why those doses sit on different scales is explained in our article on how much collagen per day.

What do hydrolysed and peptides mean on a collagen label?

Both mean the collagen has been cut into short fragments, and in practice they are the same word written two ways.

Intact collagen is around 300 kDa, built from alpha chains of about 100 kDa, according to a 2019 review in Molecules. Nothing that size is absorbed as a peptide. Heat alone denatures it into gelatin. Enzymes such as alcalase, papain or pepsin, in acid or alkaline conditions, cut it further into hydrolysed collagen with a typical weight of 3 to 6 kDa, and some marine hydrolysates come in below 600 Da.

Collagen peptides, hydrolysed collagen and collagen hydrolysate all name the same class of material, and none of the three is a legally defined quality grade. A label that says peptides tells you the protein was hydrolysed, which is true of essentially every collagen supplement sold. What tells you more is the tissue it came from and the name of the material.

Does molecular weight matter for absorption?

It matters up to a point, and beyond that point the tissue and the documentation behind the material matter more.

The absorption itself is well described. In a 2024 crossover study in Frontiers in Nutrition, healthy volunteers given 10 g of collagen hydrolysate showed prolyl hydroxyproline as the most abundant peptide in blood, along with Hyp-Gly, Gly-Pro-Hyp and Pro-Gly, and total hydroxyproline ran 36 to 47 percent above the free form. Real di- and tripeptides crossed the gut intact rather than being broken all the way down to amino acids.

The same study compared bovine hydrolysates at 2000 Da and at 5000 Da and found highly comparable peptide and amino acid concentrations in blood, with fish skin, porcine skin and bovine hide following similar overall patterns. It is close to the only direct human comparison there is, and within that range it does not point to a smaller number on a specification sheet buying much extra absorption.

What it does show is useful. Collagen peptides are absorbed as peptides, and within the studied range the size figure is not the deciding factor. The figure is rarely printed because no rule requires it and because molecular weight is a manufacturing specification rather than a nutrient, so it stays consistent only when the supplier controls it deliberately. Suppliers who do control it are the ones selling a named, documented raw material, which is the practical case for branded raw materials. Cartidyss® is specified at least 95 percent under 3000 Da, and that figure is published in its study rather than left to vary from batch to batch.

Fish collagen or bovine collagen: what separates them?

The raw material stream and who is comfortable eating it, rather than any demonstrated difference in absorption.

  • Source. Bovine collagen comes from hides and bones and delivers types I and III. Marine collagen comes from fish skin and scales, delivering type I, or from fish cartilage, delivering type II. Both are by-products of food production.
  • Diet and belief. Marine collagen suits people who avoid bovine material for religious or personal reasons. Neither is vegetarian and neither is vegan.
  • Allergen. Fish is a declared allergen under Annex II of Regulation 1169/2011 and must be labelled. The two exemptions there cover fish gelatine as a vitamin carrier and as a fining agent in beer and wine, and neither applies to a supplement. If you are allergic to fish, a marine collagen is not for you.
  • Sustainability. Marine collagen uses a discarded stream. So does bovine collagen. The impact depends on the fishery, the transport and the processing, which is one more reason to prefer a manufacturer that documents where its material comes from.
  • Absorption. On the evidence above, the species is a minor variable. Choose on tissue, type and documentation, not on the animal.

What have the trials on marine collagen measured?

Skin hydration and elasticity across the pooled trials, and wrinkle measurements and dermal thickness in the study on the specific material we use.

A 2025 systematic review and meta-analysis in the Indian Journal of Dermatology, Venereology and Leprology pooled 10 randomised trials and 646 participants and reported a standardised mean difference of 1.25 for hydration and 0.61 for elasticity. The trials were mostly in women.

What we do know is more specific. The 2021 study in Molecules was run on Cartidyss® itself: 46 women aged 45 to 59, of whom 43 completed, took 500 mg of the hydrolysed fish cartilage or placebo daily for 90 days, and skin structure was measured by imaging. The paper reported reductions in periorbital and nasolabial wrinkle measurements and increased dermal thickness and density in the Cartidyss® group. It is the same 500 mg that sits in Beauty Complete.

How do you read a collagen label in practice?

Ask four questions in order, and the back of the pack becomes much easier to read.

  • Which tissue? Skin and scales mean type I. Cartilage means type II with its own glycosaminoglycans. If the label is silent, it is most likely skin, because skin is what the industry has most of.
  • Which type, in which form? Type II at 40 mg and type II at 500 mg are different propositions with different proposed mechanisms.
  • What dose, and does it match a study? A named ingredient with a published trial at a stated dose can be checked. Cartidyss® was studied at 500 mg, and Beauty Complete contains 500 mg.
  • What is the ingredient called? A named raw material can be looked up, together with its manufacturer and its study. That is the point of naming it.

Those four questions are how we chose. Beauty Complete contains six ingredients: Cartidyss® fish cartilage collagen 500 mg from Abyss Ingredients, Hyabest® hyaluronic acid 120 mg, bio-fermented by Kewpie in Japan to a defined molecular weight, Ceramosides™ phytoceramides 30 mg from Seppic in France, vitamin C 60 mg as PureWay-C, vitamin B2 1.4 mg and biotin 50 µg. The three branded raw materials sit at the daily doses used in their own human studies, and the three vitamins at a nutritional level. Ninety days in the Cartidyss® study means taking the product every day for three months, which is why the jar is made to be kept out on a shelf rather than in a cupboard.

The vitamins carry authorised claims that belong in a skin supplement. Vitamin C contributes to normal collagen formation for the normal function of the skin. Riboflavin (vitamin B2) contributes to the maintenance of normal skin. Biotin contributes to the maintenance of normal hair and normal skin.

We have done the selection so that you do not have to. Beauty Complete, marine collagen and hyaluronic acid is where Cartidyss® sits at 500 mg per daily dose. Our skin page and our guide to collagen supplements collect the wider context. You can stop looking.

Further reading

Frequently asked questions

What is the difference between collagen type I, II and III?
Type I is the load-bearing material of skin, bone and tendon, and accounts for more than 90 percent of the collagen in the body. Type II is the framework of cartilage and comes with the cartilage's own glycosaminoglycans. Type III sits alongside type I in skin and in blood vessel walls, which is why so many products are sold as type 1 and 3: one extract from hide or skin carries both, so the label describes the raw material rather than a formulation decision.

Is marine collagen better than bovine collagen?
The difference lies in the raw material stream and in who is comfortable eating it, not in any demonstrated advantage in absorption. Marine collagen suits people who avoid bovine material for religious or personal reasons. Neither is vegetarian or vegan, and it is more useful to choose on tissue, type and documentation than on species.

Does molecular weight matter?
Up to a point. In the 2024 crossover study, hydrolysates at 2000 Da and at 5000 Da produced highly comparable peptide and amino acid concentrations in blood. It is close to the only direct human comparison there is. A supplier that publishes and controls the specification, as Abyss Ingredients does for Cartidyss®, tells you more than the number alone.

Can I take marine collagen if I am allergic to fish?
No. Fish is a declared allergen under Annex II of Regulation 1169/2011 and must always appear on the label. The two exemptions in that annex cover fish gelatine as a vitamin carrier and as a fining agent in beer and wine, and neither applies to a supplement.

Is marine collagen more sustainable?
Marine collagen uses a discarded stream, roughly 7.3 million tonnes of fish by-product a year. So does bovine collagen. The impact depends on the fishery, the transport and the processing, which is a reason to prefer a manufacturer that documents where its material comes from.

Which marine collagen does Health Royals use, and why?
Cartidyss®, a hydrolysed fish cartilage collagen from Abyss Ingredients in Brittany. It is a named raw material with a published specification and a placebo-controlled human study, and the 500 mg in Beauty Complete is the dose that study used. Beauty Complete also contains Hyabest® hyaluronic acid, Ceramosides™ phytoceramides, vitamin C, vitamin B2 and biotin.

Sources