collagen

noun

col·​la·​gen ˈkä-lə-jən 

: any of a group of fibrous proteins that occur in vertebrates as the chief constituent of connective tissue fibrils and in bones and yield gelatin and glue upon boiling with water

collagenous

kə-ˈla-jə-nəs 

adjective

Examples of collagen in a Sentence

Recent Examples on the Web

The Peptide-132 Hair Bond Repair Treatment uses a proprietary peptide complex, along with keratin, collagen, and amino acids, to repair damage, smooth frizz, and strengthen dry or overprocessed strands without weighing hair down. —Christa Joanna Lee, Allure, 23 June 2026

Bakuchiol, a popular retinol alternative and anti-aging multitasker, adds an extra boost to skin by elevating collagen production and reducing the appearance of fine lines. —Erika Reals, InStyle, 19 June 2026

Niacinamide and vitamin E work to strengthen, vitamin C brightens, AHA exfoliates and smooths, and collagen peptides help reduce the appearance of fine lines while boosting elasticity. —Claudia Fisher, Parents, 18 June 2026

The protein and amino acids in eggs help provide the building blocks needed to produce keratin and collagen, which help strengthen hair and nails. —Olivia McIntosh, Martha Stewart, 17 June 2026

Word History

Etymology

Greek kolla + International Scientific Vocabulary -gen

First Known Use

circa 1865, in the meaning defined above

Kids Definition

collagen

noun

col·​la·​gen ˈkäl-ə-jən 

: a protein that occurs in the form of fibers, does not dissolve, is found in connective tissue, and forms glue and gelatin upon boiling with water

Medical Definition

collagen

noun

col·​la·​gen ˈkäl-ə-jən 

: an insoluble fibrous protein of vertebrates that is the chief constituent of the fibrils of connective tissue (as in skin and tendons) and of the organic substance of bones and yields gelatin and glue on prolonged heating with water

collagenic

ˌkäl-ə-ˈjen-ik 

adjective

collagenous

kə-ˈlaj-ə-nəs 

adjective