Is hair made of protein or dead cells or both?

Question

Some sources say hair is made of dead cells:

• it's mentioned in many titles of Google searches, so I'm linking the Google search search

Other sources say hair is a protein filament:

• Protein filament that grows from follicles found in the dermis, or skin

I don't think protein and dead cells are the same thing. Where am I mistaken?

Answer 1

I found the answer while trying to write the question. Hopefully this helps others

We usually say that hair is “made” of a protein called keratin—that’s a bit of a simplification. As hairs become part of the shaft, they undergo a process called keratinization, in which they become filled with keratin. So, technically, instead of being made up of pure keratin, hair is made up of dead cells that are filled with and surrounded by keratin.

Source

I'd say some visualisation would be helpful, please add a new answer or propose edits to this answer