Collagen supplements and ingredients come from animal connective tissues, primarily the skin, bones, and cartilage of cattle, pigs, fish, and chickens. These raw materials are byproducts of the meat and fishing industries, processed into the powders, capsules, and liquids you find on store shelves. Each source yields slightly different types of collagen, which is why labels specify where their collagen originates.
Bovine (Cattle) Collagen
Cattle hides are one of the most widely used raw materials for collagen production. The skin, bones, tendons, and ligaments of cows are rich in type I collagen, the most abundant form in the human body. Type I collagen is the structural protein found in your own skin, bones, and connective tissue, which is why bovine collagen is marketed heavily for skin and joint support.
Cowhide is collected as a byproduct of beef processing. The raw hide goes through cleaning steps to remove fat, hair, and pigments before the collagen is extracted using acid solutions. The process typically involves soaking hide in acetic acid for several days, sometimes with the help of digestive enzymes like pepsin to break down the protein structure. The result is purified collagen that can be dried and ground into powder.
Porcine (Pig) Collagen
Pig skin is another major industrial source, producing type I collagen very similar to the bovine version. Porcine collagen has been used for decades in gelatin production (gelatin is simply a partially broken-down form of collagen) and remains a staple in food manufacturing, pharmaceutical capsules, and some supplement lines. The extraction process mirrors the bovine method: cleaning, fat removal, acid treatment, and drying.
One reason porcine collagen is so common is sheer volume. Pig skin is abundantly available from pork processing, making it inexpensive to source. However, porcine collagen is unsuitable for people who avoid pork for religious or dietary reasons, which has driven demand for alternative sources.
Marine (Fish) Collagen
Fish collagen comes primarily from the skin and bones of fish, and it’s the fastest-growing segment of the collagen market. Fish skins are rich in type I collagen and carry two advantages over mammalian sources: they don’t conflict with religious dietary restrictions around beef or pork, and they carry no risk of transmitting cattle-related diseases.
The species most commonly used include salmon, codfish, Alaska pollock, and mackerel. In most cases, the skins are waste products from the commercial fishing industry that would otherwise be discarded. Fish scales are also used, though skin remains the primary source. Research on salmon and codfish skin collagen has shown it performs comparably to mammalian collagen in applications like wound healing and skin care, with collagen isolated from these species showing no irritation when tested on human skin.
Marine collagen does come with a quality consideration. Testing of fish-derived collagen supplements has found trace levels of heavy metals, including chromium, arsenic, lead, and cadmium, likely picked up from the aquatic environment. Mercury, by contrast, was rarely detected. The amounts found in studies have generally fallen within safe daily intake limits, but this is one reason sourcing transparency and third-party testing matter when choosing a marine collagen product.
Chicken Collagen
Chicken is the go-to source for type II collagen, which is the dominant collagen in cartilage rather than skin or bone. The richest part of the chicken for this purpose is the sternum (breastbone) cartilage. Extracts from chicken sternal cartilage naturally contain a matrix of type II collagen along with two other joint-supporting compounds: chondroitin sulfate and hyaluronic acid.
This combination is why chicken-derived collagen is often marketed specifically for joint health. In a randomized, placebo-controlled trial, women who took 500 mg of hydrolyzed chicken sternal cartilage extract twice daily saw improvements in skin elasticity and reductions in wrinkling, suggesting the benefits extend beyond joints. The extract supported accumulation of types I and III collagen in the skin as well.
Eggshell Membrane
A less common but emerging source is the thin membrane found between the eggshell and the egg white. This membrane is roughly 10% collagen by protein content, primarily types I, V, and X. The inner membrane contains mostly types I and V, while type X appears in both the inner and outer layers. The remaining 70 to 75% of the membrane’s protein is made up of other structural proteins and glycoproteins.
Eggshell membrane is harder to work with than skin or bone. Extracting its proteins requires more aggressive processing, including combinations of heat, pressure, acids, alkalis, or enzymes like papain and pepsin. The difficulty of extraction keeps eggshell membrane a niche source, but it appeals to people looking for collagen that doesn’t come from mammalian or fish sources.
How Raw Tissue Becomes Collagen Powder
Regardless of the animal source, the journey from raw tissue to supplement follows a similar path. First, the tissue is cleaned and pretreated to remove fat, hair, scales, or other non-collagen material. Then the collagen is extracted, usually by soaking the tissue in an acid solution for one to several days.
At this stage, you have intact collagen molecules, which are large and not easily absorbed by the gut. To make them bioavailable, manufacturers apply heat above 40°C to denature the collagen, separating its tightly wound triple-helix structure into individual protein chains. Those chains are then broken into smaller fragments using proteolytic enzymes like alcalase, papain, or pepsin. The resulting product, hydrolyzed collagen, consists of small peptides with low molecular weight (roughly 3 to 6 kilodaltons) that dissolve easily in liquid and are readily absorbed during digestion.
This is why you’ll see terms like “hydrolyzed collagen” and “collagen peptides” on labels. They refer to the same thing: collagen that has been enzymatically broken into small, absorbable pieces.
Collagen Types and Their Sources
Not all collagen is interchangeable. There are at least 28 known types, but three dominate supplements:
- Type I is the most abundant collagen in the human body, concentrated in skin, bone, tendons, and ligaments. Bovine hide, pig skin, and fish skin are all rich sources.
- Type II is the primary collagen in cartilage, where it makes up nearly 80% of total collagen content. Chicken sternum cartilage is the main commercial source.
- Type III is always found alongside type I but in thinner fibrils. It’s concentrated in skin, blood vessels, and tissues with high elasticity. Bovine and porcine sources contain both types I and III.
When a supplement label says “types I and III,” it almost certainly comes from bovine, porcine, or marine sources. A label emphasizing “type II” points to chicken cartilage.
Lab-Grown and Recombinant Collagen
For people who want collagen without any animal involvement, recombinant collagen is the only true option. This is collagen produced by genetically engineered microorganisms, most commonly E. coli bacteria. Scientists insert collagen-producing gene sequences into the bacteria, which then manufacture collagen-like proteins during fermentation.
Interestingly, over 100 collagen-like protein sequences have been identified in various bacterial species. Researchers have built functional collagen constructs using genes from Streptococcus pyogenes, Methylobacterium, and Solibacter usitatus, among others. These bacterial collagen-like proteins form the same triple-helix structure found in animal collagen but are produced without any animal tissue, eliminating concerns about disease transmission or religious dietary restrictions.
Recombinant collagen is currently used more in biomedical research and wound-healing applications than in consumer supplements. Most products labeled “vegan collagen” on the supplement market are not actually collagen. They’re blends of vitamins, minerals, and amino acids intended to support your body’s own collagen production. True recombinant collagen supplements exist but remain uncommon and more expensive than animal-derived options.