Collagen peptides come primarily from animal byproducts, specifically the skin, bones, scales, and connective tissues of cows, pigs, chickens, and fish. These raw materials are broken down through a multi-step process that converts large, tough collagen proteins into tiny fragments small enough for your body to absorb. The global meat and seafood processing industries generate enormous quantities of collagen-rich waste, and peptide production repurposes what would otherwise end up in landfills.
Bovine Sources: Skin and Bone
The most common source of collagen peptides is cattle. Calf skin and bone are the primary raw materials for industrial collagen production, and they yield predominantly type I collagen, the same type that makes up about 90% of the collagen in your own body. Cowhide in particular is rich in collagen and available in large volumes from the beef industry, making it the backbone of most collagen supplement brands you’ll see on shelves.
Bovine collagen extracted from hide and bone retains the same triple-helix structure as native collagen before it’s broken down into peptides. This structural similarity is one reason it’s been the industry standard for decades. If a collagen peptide product doesn’t specify its source, it’s most likely bovine.
Marine Sources: Fish Skin, Scales, and Bones
Marine collagen comes from fish processing byproducts: skin, scales, bones, fins, swim bladders, and cartilage. Fish skin is the most prized source because it contains type I collagen at a purity level of roughly 70%, though this varies by species, age, and the water temperature the fish lived in. Fish scales and bones also yield type I collagen but require different extraction conditions.
The range of fish species used is broad. Tuna (bigeye, bluefin, and yellowfin), sea bass, catfish, sturgeon, and even blue sharks all contribute to marine collagen production. Blue shark cartilage is notable because it yields type II collagen, which is the type found in your joint cartilage rather than your skin and bones. Most other fish parts produce type I.
Cold-water fish like cod and halibut produce collagen with different physical properties than warm-water species like tilapia and tuna. Cold-water fish collagen has lower thermal stability, meaning it denatures at lower temperatures. This can affect how the collagen behaves in supplements and cosmetics, though the amino acid profile remains similar across species.
Porcine and Poultry Sources
Pig skin is another major source, particularly for medical and clinical applications. Porcine collagen is structurally and biochemically very similar to human collagen, which is why it’s widely used in wound-healing products and surgical materials in addition to supplements. The collagen extracted is predominantly type I, pulled from the dermis (the thick inner layer of skin) through acid-based hydrolysis.
Chicken collagen typically comes from cartilage, particularly the sternum (keel bone) cartilage. This is one of the few common sources of type II collagen, making chicken-derived products popular in joint health supplements. Type II collagen is the primary structural protein in cartilage, so it targets a different need than the type I collagen from bovine, marine, or porcine sources.
How Raw Collagen Becomes Peptides
Native collagen is a massive molecule, roughly 300,000 daltons in molecular weight, about 280 nanometers long, and shaped like a twisted rope of three intertwined protein chains. Your digestive system can’t efficiently absorb something that large. The manufacturing process chops it down to fragments of just 3,000 to 6,000 daltons, roughly 1/50th to 1/100th the size of the original molecule.
The process happens in stages. First, raw animal tissue is cleaned and pretreated with acid or alkaline solutions to remove fats, minerals, and non-collagen proteins. Then the collagen is heated above 40°C, which unravels the triple-helix structure into loose individual chains. This step essentially converts collagen into gelatin.
Next comes hydrolysis, the step that distinguishes collagen peptides from gelatin. Enzymes like pepsin, trypsin, or alcalase are added to cut the gelatin chains at specific points along their length, producing the small peptide fragments. Enzymatic hydrolysis is preferred because it works under mild conditions and allows precise control over the final peptide size. Chemical hydrolysis using acids or bases can achieve a similar result but is less targeted. Many manufacturers use a combination: chemical hydrolysis first to produce gelatin, followed by enzymatic hydrolysis to reach the desired molecular weight.
The result is a powder of small, soluble peptide chains that dissolve easily in liquid and are readily absorbed through the gut wall. This is why collagen peptide supplements dissolve in coffee or smoothies while a chunk of cowhide obviously would not.
All Sources Are Industry Byproducts
No animals are raised specifically for collagen production. The raw materials come from waste streams of existing meat, poultry, and seafood processing. Hides, bones, fish skins, and scales are generated in massive volumes and would otherwise pose a disposal problem. Repurposing these protein-rich materials into collagen peptides reduces environmental waste while creating a high-value product.
The seafood industry in particular has embraced this approach. Fish bones, scales, and skin from filleting operations represent a largely underutilized resource, and extracting collagen from them adds economic value to processing side streams that would typically be discarded or rendered into low-grade fishmeal.
Lab-Made and Vegan Alternatives
A small but growing segment of collagen production bypasses animals entirely. Recombinant collagen is made by inserting human collagen genes into microorganisms, most commonly E. coli bacteria, yeast, or plant cells, then harvesting the collagen-like proteins they produce through fermentation. The E. coli expression system currently accounts for roughly 40% of clinically used recombinant proteins and can yield larger quantities than mammalian cell systems.
These engineered microbes can produce collagen with the characteristic triple-helix structure found in animal collagen, though getting it to perfectly match human collagen requires co-expressing the enzymes responsible for a key chemical modification called hydroxylation. Without that step, the resulting protein is less stable than natural collagen.
Products marketed as “vegan collagen” take a slightly different approach. One commercially available ingredient, VeCollal, consists of fermented amino acids derived from plant-based materials, produced by a bacterium called Corynebacterium glutamicum. Rather than being true collagen, it provides the specific amino acid building blocks your body uses to make its own collagen. A type 21 collagen has also been developed through biotechnology and marketed as the first vegan bioidentical human collagen for skincare, though these products remain niche compared to animal-derived peptides.
The synthetic production of collagen through microbes is still limited by the complexity of the molecule. Factors like fermentation temperature, pH, oxygen levels, and the quality of the microbial strain all influence the final product. Scaling up to match the volume and cost-effectiveness of animal-derived collagen remains a challenge, which is why the vast majority of collagen peptides on the market still come from cows, fish, pigs, and chickens.