How to Use keratin in a Sentence

keratin

noun

• 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
• Horns are made of keratin — the same protein in our nails and hair.
  — Jane Alexiadis, The Mercury News, 26 Jan. 2017
• Half the head is bone, half is covered with hide and keratin.
  — WIRED, 26 Aug. 2023
• 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
• Six of the seven species have hard shells fused to their ribs and overlaid with keratin scutes.
  — National Geographic, 10 Oct. 2019
• 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
• These parts are composed of keratin, the same tissue that makes up hair, skin, and nails.
  — Laura Baisas, Popular Science, 24 May 2023
• Their horns, which are made of keratin, also grow back.
  — Dac Collins, Outdoor Life, 16 Jan. 2025
• Once applied, the ink reacts with the proteins and keratin in the skin, and darkens over 24-36 hours.
  — Anna Tingley, Variety, 24 Oct. 2023
• 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
• It’s made of keratin—the same protein our fingernails and hair are made of.
  — National Geographic, 26 June 2016
• With a keratin lash lift, more protein is added back into the lash, Imani says.
  — Sara Spruch-Feiner, Town & Country, 7 Mar. 2020
• Baleen–or whalebone–is a hard substance made up of keratin.
  — Laura Baisas, Popular Science, 21 Feb. 2024
• My first keratin treatment was just a few months after the birth of my first daughter.
  — Liz Krieger, Allure, 15 Apr. 2025
• 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
• Now that the bone is finished healing and the keratin is growing, the team will mostly have to be patient.
  — Laura Baisas, Popular Science, 10 Apr. 2025
• The bacteria erodes the keratin in the outer layer of the skin, causing the skin to become pitted.
  — Sarah Bradley, Health, 6 Feb. 2025
• These can be things like oils, butters, plant extracts, and keratin.
  — Louryn Strampe, WIRED, 2 Feb. 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
• The hero ingredient is the L-arginine, which is an amino acid found in keratin, a.k.a.
  — Natasha Marsh, Allure, 7 Apr. 2025
• Bird feathers, like human hair and nails, are made of a protein called keratin.
  — New York Times, 21 Mar. 2018
• Its scales are made of keratin and are used in traditional medicines.
  — Fox News, 23 July 2019
• And in nail strengtheners, formaldehyde is supposed to bond with the nail’s keratin.
  — Marci Robin, Allure, 29 Jan. 2024
• Glycine, a key amino acid, helps relink keratin chains to reduce breakage and seal split ends.
  — Deanna Pai, Vogue, 14 July 2024
• Insulin or insulin-like substances speed up the growth of keratin, a key protein in your skin.
  — Alisa Hrustic, SELF, 16 June 2025
• Reduces Breakage Hair is made of keratin, a type of protein.
  — Cristina Mutchler, Verywell Health, 29 May 2025
• Living animals tend to have tails with weapons that are made of keratin, like the quills of a porcupine or the scales of a pangolin.
  — Nicholas St. Fleur, New York Times, 16 Jan. 2018
• Feathers are made of keratin, the same compound as our hair and fingernails.
  — Ian Rose, Smithsonian Magazine, 10 June 2025
• It’s enriched with hydrolyzed keratin, which penetrates the hair cuticle and fills in the gaps caused by breakage for stronger bonds.
  — Jessie Quinn, StyleCaster, 4 Aug. 2025