Collagen

What is collagen?

Updated 9 Nov 2026

Short answer

Collagen is a family of proteins that strengthen skin, bone, tendons and cartilage.[1] There are at least 28 types; type I makes up over 90% of the collagen in the body, and type II is found mostly in cartilage.[2][3] Supplements contain collagen from cattle, pigs, fish or chicken. Collagen peptides are collagen cut into short pieces with enzymes.[4][5]

Sources (5)

  1. COL1A1 gene: MedlinePlus Genetics. MedlinePlus, US National Library of Medicine, 2019. medlineplus.gov
  2. Biochemistry, Collagen Synthesis. Rahimi N, Launico MV StatPearls, 2026. PMID 29939531
  3. COL2A1 gene: MedlinePlus Genetics. MedlinePlus, US National Library of Medicine, 2024. medlineplus.gov
  4. Hydrolyzed Collagen-Sources and Applications. León-López A, Morales-Peñaloza A, Martínez-Juárez VM, Vargas-Torres A, Zeugolis DI, Aguirre-Álvarez G Molecules, 2019. PMID 31703345
  5. Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study. Lugo JP, Saiyed ZM, Lane NE Nutr J, 2016. PMID 26822714

More about collagen

Can you get collagen from food?What is collagen used for?How long does collagen take to work?Is collagen safe?Does collagen help joint pain?Does collagen help your skin?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.