Type I Collagen - Found in skin, tendons, blood vessels, ligaments, organs, and the cornea of the eye. This type of collagen also comprises about 50% of the protein matrix of bone.
Type I Collagen is the most abundant form of collagen in the body.
Type II Collagen - Found in hyaline cartilage, the intervertebral discs of the spine and the vitreous humor of the eye.
Type III Collagen - Found in skin, tendons, intestines, artery walls and the uterus.
There is much confusion regarding collagen types I, II and III. The fact is that all three types can provide health benefits. More importantly (and often overlooked) is the collagen source and the manufacturing process.
Types I & III collagen are most often derived from fish (marine), cow (bovine) or pig (porcine) sources. Fish (marine collagen) is widely considered to be the superior form and the most premium source of collagen - but not all marine collagen is created equal. Marine collagen is sourced from various fish species and can be produced from fish skin (low grade), skin and scale (mid-grade) or exclusively from fish scale (high grade). withinUs TruMarine™ Collagen is a premium select grade collagen, produced exclusively from the scales of sustainably sourced fish found in the deep, clean waters of the South Pacific Ocean. TruMarine™ uses a proprietary enzymatic process to produce an ultra-pure form of collagen, which provides superior bioavailability.
Type II collagen is a less popular form of collagen most commonly sourced from chicken sternum.
Note: If a collagen supplement does not list the raw material source it is very likely a lower (cheaper) grade collagen derived from bovine or porcine sources.