Introduction: why the source of your collagen matters
Why the origin of your collagen counts: type specificity and your goal
Collagen has gone from a niche subject to the most popular anti-ageing and joint supplement there is. But faced with the sheer range of products — from bovine to marine, from type I to type II — consumers come up against a basic question: is the source what determines the effect? The answer is a nuanced one, and it depends on your primary goal. The origin determines which type of collagen the product contains, and that type bears on what you are aiming at, whether skin, joints or bone. But the real key to effectiveness lies in the processing, meaning hydrolysis, and in the bioavailability that results from it. Only once collagen has been broken down into small peptides can those peptides be absorbed intact from the gut.
The main goals people take collagen for, and which types match them
Most users focus on two main areas: structural improvement of skin and hair, and strengthening of joints and bone.
✅ Type I: essential for skin elasticity, bone density, tendons and ligaments. Type I is the most abundant protein in the body and provides the tensile strength of tissue¹.
✅ Type II: the most important building block for cartilage — hyaline cartilage — in the joints.
✅ Type III: supports the elasticity of skin and the structure of blood vessels.
Age-related collagen loss as the central problem for regeneration
From around the age of 25, the body's own collagen production begins to fall by roughly 1.0% a year. This steady decline, compounded by external factors such as UV radiation and smoking, leads to visible skin ageing, lower bone density and decreasing elasticity in tendons and ligaments. Fibroblasts (skin), chondrocytes (cartilage) and osteoblasts (bone) each build the collagen matrix of their tissue. Collagen peptides supply the amino acids these cells use as raw material¹⁶.
The real key to effectiveness: hydrolysis and bioactive peptides
From fibrous protein to bioactive peptide: the hydrolysis process
Intact, raw collagen — as found in broth or gelatine, for instance — is a large protein of some 300,000 daltons, and the body digests it primarily as a simple source of protein. The transformative effect of collagen supplements rests on hydrolysis: a controlled enzymatic process in which the native protein is broken into tiny fragments, the collagen peptides². Only these peptides act as specific signalling agents in the body, and only they can pass through the gastrointestinal barrier intact.
Why molecular weight (the dalton value) is critical
Bioavailability — the percentage of a substance that actually reaches the bloodstream — depends directly on molecular weight³. Experts recommend collagen peptides with a molecular weight below 2,000 daltons. Only at that small size can the peptides be absorbed quickly, via specialised transporters in the intestinal lining. An optimal peptide profile often sits between 500 and 1,000 daltons, since these di- and tripeptides show the highest absorption rates¹⁷.
Amino acids as signalling agents, and tissue targeting
The specific effect of collagen peptides lies not in the quantity of amino acids as such, but in the signalling function of the peptides that remain. The fragments containing hydroxyproline are particularly important — prolyl-hydroxyproline and hydroxyprolyl-glycine, for example. After intake these circulate in the bloodstream for several hours and have been detected in the target tissues, where the fibroblasts sit. Those cells build the collagen and hyaluronic acid of the dermis, and the peptides supply the amino acids they use as raw material⁴’¹⁸.
The common collagen sources in detail: type composition and benefits
1. Bovine collagen: the all-rounder for strength and structure
Bovine collagen is the most widespread and the most researched source, and it is obtained mainly from the hide, bones and connective tissue of cattle.
Types I and III – skin, bone and muscle
Bovine collagen supplies mainly type I, together with a significant proportion of type III collagen.
✅ Type I: provides the tensile strength of the dermis, bone and tendons.
✅ Type III: ensures elasticity and matters for the structure of vessels and organs. Studies have examined bovine collagen with respect to bone mineral density (BMD) and joint parameters⁵.
Choosing the right molecular weight is decisive for high bioavailability. If that quality matters to you: at the Kollagen Institut you will find hydrolysed collagen peptides whose size is consistently below 2,000 daltons: collagen products.
The high glycine and proline content
Bovine collagen has a very high proportion of glycine and proline. Glycine, the smallest amino acid, is not only essential for the formation of collagen but also plays a key part in creatine synthesis. Glycine is therefore one of the amino acids the body draws on for collagen and for creatine alike. Studies in older adults have recorded body composition and muscle strength¹⁹’⁶.
2. Marine collagen (fish): the bioavailability star for skin
Marine collagen is obtained from the skin and scales of fish such as cod and tilapia. Its efficiency has made it the front-runner in beauty and anti-ageing.
Pure type I and absorption efficiency
Marine collagen consists almost entirely of type I collagen⁷. Its decisive advantage often lies in its smaller peptide size, frequently below 1,000 daltons, which is credited with potentially faster and higher bioavailability than bovine collagen. Studies using marine peptides have recorded skin elasticity and wrinkle depth over several weeks⁸.
Environmental considerations and heavy-metal control
Choosing marine sources calls for particular care. Although fish by-products are being used — a form of upcycling — sustainable practice and certification matter, whether the fish is wild-caught or farmed. Rigorous testing for heavy-metal contamination, mercury for instance, is essential⁹. High-quality manufacturers therefore use fish from controlled, clean waters and provide certificates of analysis.
3. Chicken collagen (poultry): the specialist for joints and cartilage
Collagen from poultry, usually obtained from breast cartilage, is the source of choice when the focus is explicitly on cartilage regeneration.
Type II – the main building block of hyaline cartilage
Chicken collagen is the richest source of type II collagen, the main component of hyaline cartilage¹⁰. Type II is thus the collagen type the cartilage matrix itself is built from. Studies on type II preparations accordingly record mostly joint parameters.
How native (undenatured) type II works (UC-II)
Chicken collagen is often also sold as UC-II, undenatured type II collagen, which works through an entirely different mechanism from hydrolysed peptides. Rather than serving as a nutrient, UC-II acts through the immunomodulating mechanism of oral tolerance in the gut¹¹. It interacts with the Peyer's patches of the gut-associated immune system. Studies on UC-II have examined this oral-tolerance pathway²⁰.
4. Porcine collagen: economical, and structurally similar
Collagen from pig skin and bone is structurally very similar to bovine collagen and is often used as a lower-cost alternative in Europe and Asia.
Type composition and use
Porcine collagen likewise supplies mainly type I and type III, and is therefore used in skin and bone preparations²¹. Its bioavailability is comparable to that of the bovine source, but depends just as heavily on the degree of hydrolysis²². It is important to bear in mind the cultural and religious restrictions that rule this source out for many consumers.
Quality criteria and safety – what you need to know about your collagen
Purity, transparency and analytical quality
Control of heavy metals and contaminants
The raw materials for collagen come from animal by-products such as skin and bone. Strict control for contamination is therefore of the highest importance. High-quality manufacturers have their products tested in independent laboratories for microbial load, pesticides and above all heavy metals — lead, cadmium and mercury. Only analytically pure products should be consumed⁹.
BSE/TSE risk with bovine collagen
With bovine collagen, the risk of transmitting prions must be excluded — bovine spongiform encephalopathy (BSE), or transmissible spongiform encephalopathies (TSE). Reputable suppliers make sure their collagen is obtained from tissues that carry minimal risk, skin rather than nerve tissue for instance, and that the hydrolysis process involves the high temperatures and acids that inactivate prions²⁶.
Safety through transparency: purity and traceable origin require documentation without gaps. Our collagen is obtained from European raw materials and manufactured exclusively in Germany. You can read the certificates of analysis and quality standards for all the Kollagen Institut's collagen sources — bovine, fish and chicken: collagen products.
Ethical and sustainable sourcing
Why certified pasture-raised (grass-fed) matters
With bovine and porcine collagen in particular, sourcing from controlled free-range or pasture farming means a lower burden of hormones and antibiotics, and is the better ethical choice⁶. This not only safeguards animal health but also has a positive effect on the quality of the raw material.
Upcycling and the circular economy
Collagen production often uses by-products that would otherwise have to be disposed of, such as fish skin and cattle hides. In this respect collagen peptides are an excellent example of upcycling in the food industry, which brings a positive ecological footprint with it²⁷.
Getting the most from collagen, and vegan alternatives
Optimal dosing and synergy with cofactors
The dose-response relationship
Most clinical studies showing positive results for skin, joints and bone use doses between 5 g and 15 g of hydrolysed collagen peptides a day¹⁹’²³. The Kollagen Institut daily serving is 5 g; the higher amounts used in studies correspond to two or three servings. These studies typically run for 8 to 12 weeks of daily intake before their endpoints are measured²³.
Vitamin C, the obligatory cofactor
A high-quality product often already contains vitamin C, since this is an obligatory cofactor for the enzymes — prolyl and lysyl hydroxylase — needed to stabilise and cross-link collagen fibres in the body¹³. Without an adequate intake of vitamin C, collagen synthesis can be severely limited²⁴.
Vegan collagen boosters: the alternative for plant-based diets
Since collagen is by definition an animal protein, there is no such thing as genuine vegan collagen. There are, however, collagen-precursor supplements, which aim to support the body's own collagen production.
The precursor strategy
Vegan collagen boosters contain the essential amino acids and cofactors the body needs for its own collagen synthesis:
✅ Amino acids: proline, glycine and lysine.
✅ Minerals: zinc and copper, the latter important for the enzyme lysyl oxidase.
✅ Vitamins: vitamin C, as mentioned above, and vitamin A (retinol) to regulate collagen metabolism²⁸.
A breakthrough through fermentation
Current research is focusing on producing collagen peptides with the help of genetically modified yeasts and bacteria, through fermentation. In future this technique could deliver genuine, type-specific, structurally identical collagen with no animal components.
Conclusion and what to buy
The myth of the type boom
The choice of source matters, because it determines the dominant collagen type (I, II, III), which in turn bears on your goal — skin versus cartilage. But the processing (hydrolysis) and the low molecular weight, ideally below 2,000 daltons, are what decide the bioavailability and signalling effect of the peptides in your body. The type boom, cramming numerous collagen types into one product, is often a marketing myth; concentrating on the main type that matches your goal, in pure hydrolysed form, is the simpler approach.
Five points to check before you buy
Apply this checklist when you decide:
-
Define your goal: choose the source by type — marine or bovine for skin and bone, chicken for cartilage.
-
Check the hydrolysis: look for a stated molecular weight, ideally < 2,000 Da.
-
Demand purity: insist on transparency about heavy metal and contaminant testing.
-
Traceable origin: look for documented sourcing and production you can actually follow.
-
Use the synergies: choose a product that already contains vitamin C, or take it separately.
References
¹ Rémond, D., et al. (2009). The challenge of protein digestion and absorption: a review. J Physiol Biochem, 65(1), 1-12.
² Lupu, M. A., et al. (2020). Beneficial effects of food supplements based on hydrolyzed collagen for skin health. Int J Med Sci, 17(12), 1753-1766.
³ Iwai, K., et al. (2005). Identification of food-derived collagen peptides in human blood after oral ingestion. J Agric Food Chem, 53(16), 6531-6536.
⁴ Shigemura, Y., et al. (2014). Collagen derived peptides increased type I collagen and MMP-1 mRNA expressions in human fibroblasts. Biochem Biophys Res Commun, 443(2), 643-647.
⁵ Zdzieblik, D., et al. (2018). Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men. Br J Nutr, 120(1), 8-15.
⁶ Rippe, J. M., et al. (2021). The benefits of hydrolyzed collagen peptides to improve body composition and reverse sarcopenia. J Am Coll Nutr, 40(7), 594-600.
⁷ Viguet-Carrin, S., et al. (2006). The different types of collagen. Joint Bone Spine, 73(5), 516-521.
⁸ Jafari, H., et al. (2020). Collagen from fish skin as a source of bioactive peptides: A review. J Food Sci Technol, 57(1), 1-13.
⁹ Bendas, E., & Luttmann, A. (2020). Heavy metals contamination in fish and their health risks. J Food Saf, 40(6), e12817.
¹⁰ Lugo, J. P., et al. (2013). Undenatured type II collagen (UC-II) for joint support: a randomized, double-blind, placebo-controlled study in healthy volunteers. J Int Soc Sports Nutr, 10(1), 48.
¹¹ Faria, S. B., et al. (2021). Oral tolerance induction and Type II collagen in autoimmune diseases. Int J Clin Rheumatol, 16(1), 1-10.
¹² Figueres, L., et al. (2022). Safety and efficacy of a marine collagen peptide diet in mild to moderate skin aging. J Cosmet Dermatol, 21(1), 329-335.
¹³ DePhillipo, N. N., et al. (2018). Efficacy of vitamin C supplementation on collagen synthesis and wound healing: a systematic review. J Orthop Res, 36(11), 3097-3101.
¹⁴ Porfírio, E., & Fanaro, G. B. (2016). Collagen supplementation as a complementary therapy for the prevention and treatment of osteoporosis and osteoarthritis: a systematic review. Braz J Med Biol Res, 49(5), e5152.
¹⁵ Dar, Q. A., et al. (2017). Effects of specific collagen on markers of joint metabolism and pain. Osteoarthr Cartilage, 25(8), 1251-1260.
¹⁶ Varani, J., et al. (2006). Decreased collagen production in chronologically aged skin: roles of age-dependent gene expression and enzyme activity. Am J Pathol, 168(6), 1861-1868.
¹⁷ Postlethwaite, A. E., et al. (1978). Chemoattractant peptides from collagen: a signal to repair. Proc Natl Acad Sci U S A, 75(2), 871-875.
¹⁸ León-López, A., et al. (2019). Hydrolyzed Collagen—Sources and Applications. Molecules, 24(22), 4031.
¹⁹ Mandl, I., et al. (1979). Glycine as a collagen-derived amino acid and its role in creatine synthesis. Adv Exp Med Biol, 105, 473-484.
²⁰ Bakilan, F., et al. (2016). Effects of oral type II collagen in the treatment of rheumatoid arthritis: a randomized, controlled trial. J Clin Rheumatol, 22(5), 297-302.
²¹ Sricharoen, N., et al. (2020). Porcine Skin as a Major Source of Type I Collagen. Molecules, 25(18), 4165.
²² Asserin, J., et al. (2015). The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and clinical studies. J Cosmet Dermatol, 14(4), 291-301.
²³ Proksch, E., et al. (2014). Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. Skin Pharmacol Physiol, 27(3), 113-119.
²⁴ Pullar, J. M., et al. (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8), 866.
²⁵ Barati, M., et al. (2020). The effect of hydrolyzed collagen peptide supplementation on body composition and muscle strength in sarcopenic elderly. J Clin Med, 9(12), 4124.
²⁶ WHO/FAO/OIE (2018). Guidelines for the assessment of bovine spongiform encephalopathy (BSE) risk in materials of animal origin.
²⁷ Liu, Y. et al. (2021). Collagen and gelatin from aquatic products and by-products: Extraction, properties, and applications. Trends Food Sci Technol, 118, 114-124.
²⁸ Pu, Y. C., et al. (2021). The importance of vitamins and minerals for collagen synthesis and anti-aging. Int J Cosmet Sci, 43(4), 389-399.
²⁹ Matsuda, N., et al. (2006). Effects of ingestion of a hydrolyzed collagen supplement on elderly skin. J Dermatol Sci, 41(3), 177-183.
Image credits
MMPhoto21, Techa Tungateja, Olemedia, artisteer und istockphoto.com