How to Use keratin in a Sentence

keratin

noun
  • Half the head is bone, half is covered with hide and keratin.
    — WIRED, 26 Aug. 2023
  • Horns are made of keratin — the same protein in our nails and hair.
    — Jane Alexiadis, The Mercury News, 26 Jan. 2017
  • The horns are made of sheaths of keratin, like true horns, but shed every year like a true antler.
    — Matt Wyatt, ExpressNews.com, 13 Feb. 2020
  • These can be things like oils, butters, plant extracts, and keratin.
    — Louryn Strampe, WIRED, 2 Feb. 2025
  • Six of the seven species have hard shells fused to their ribs and overlaid with keratin scutes.
    — National Geographic, 10 Oct. 2019
  • These parts are composed of keratin, the same tissue that makes up hair, skin, and nails.
    — Laura Baisas, Popular Science, 24 May 2023
  • Salon keratin treatments often claim to be free of the f-word too.
    — Olivia Fleming & Jenna Rosenstein, Harper's BAZAAR, 12 Aug. 2019
  • Its scales are made of keratin and are ground up to use in traditional medicines.
    — Washington Post, 23 July 2019
  • As the feathers grow, the keratin keeps a record of the bird’s diet, much like the rings of a tree.
    — New York Times, 21 Mar. 2018
  • My first keratin treatment was just a few months after the birth of my first daughter.
    — Liz Krieger, Allure, 15 Apr. 2025
  • Its scales are made of keratin and are used in traditional medicines.
    — Fox News, 23 July 2019
  • It’s made of keratin—the same protein our fingernails and hair are made of.
    — National Geographic, 26 June 2016
  • Bird feathers, like human hair and nails, are made of a protein called keratin.
    — New York Times, 21 Mar. 2018
  • With a keratin lash lift, more protein is added back into the lash, Imani says.
    — Sara Spruch-Feiner, Town & Country, 7 Mar. 2020
  • Just like human fingernails and hair, scutes are made of keratin.
    — Jenny Staletovich, Miami Herald, 2 May 2026
  • The scrub goes straight to the root of the problem—keratin buildup around the hair follicles.
    — Cheryl Fenton, Parents, 14 June 2026
  • Glycine, a key amino acid, helps relink keratin chains to reduce breakage and seal split ends.
    — Deanna Pai, Vogue, 14 July 2024
  • Scroll to shop our most popular picks, from keratin-rich hair masks, to lightweight oils.
    — Conçetta Ciarlo, Vogue, 8 Oct. 2025
  • The fungus grows best in warm, damp places and feeds on keratin, a protein that makes up your skin, hair, and nails.
    — Brandi Jones, Health, 5 July 2025
  • Polyvinyl pyrrolidone sticks to the keratin in hair shafts and, like isopentane, makes the hairs stand up straight for a clean shave.
    — Wired Staff, WIRED, 1 Nov. 2006
  • Feathers are made of keratin, the same compound as our hair and fingernails.
    — Ian Rose, Smithsonian Magazine, 10 June 2025
  • Insulin or insulin-like substances speed up the growth of keratin, a key protein in your skin.
    — Alisa Hrustic, SELF, 16 June 2025
  • Once the virus is gone, the growths, which are made of the same keratin found in hair and nails, eventually fall off.
    — Stephanie Pappas, Scientific American, 14 Aug. 2025
  • An excess of keratin, a protein found in hair, causes tiny red bumps that look like goosebumps.
    — Carrie Madormo, Health, 10 Sep. 2025
  • The grays are baleen whales that have sheets of keratin, a substance like fingernails, instead of teeth.
    — Phil Diehl, sandiegouniontribune.com, 9 Aug. 2017
  • And in nail strengtheners, formaldehyde is supposed to bond with the nail’s keratin.
    — Marci Robin, Allure, 29 Jan. 2024
  • Without as much keratin, nails can become weaker and more brittle.
    — Jocelyn Solis-Moreira, Flow Space, 13 Feb. 2026
  • After all, these items are all composed of keratin, a biodegradable protein.
    — Lauren Landers, Better Homes & Gardens, 3 Aug. 2024
  • The formula is packed with keratin—a protein that is a major building block for hair.
    — Sophie Wirt, InStyle, 26 Feb. 2026
  • The formula is packed with keratin—a protein that is a major building block for hair.
    — Sophie Wirt, InStyle, 30 Jan. 2026

Some of these examples are programmatically compiled from various online sources to illustrate current usage of the word 'keratin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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