Rhino horns are made mostly of keratin , the same tough protein that makes up human hair and fingernails, with additional strengthening deposits of calcium and melanin inside the horn.

What rhino horns are made of

  • Main ingredient: keratin, a fibrous protein also found in hair, nails, hooves, and bird beaks.
  • Inner core: dense deposits of calcium (for extra hardness) and melanin (to protect from sun damage).
  • Overall structure: solid “block” of keratin, not hollow, growing in layers from specialized skin cells on the rhino’s nose.

Researchers once thought rhino horn was just a clump of compressed hair, but microscopic and CT-scan studies showed it is a solid keratin structure with a reinforced core rather than loose hair fibers.