what is protein?

Protein is what gives the hair its strength and structure. Hair is about 70% keratin protein by nature. Proteins serve different functions and roles in hair care. Some enhance elasticity, while others reduce it. These proteins bind to the hair cuticle and help temporarily rebuild any weakened areas. Protein-based products reinforce the hair shaft, and it help it remain strong enough to fight breakage. Here is a great test...and the link to the article is below- it is the easiest way to explain/understand- your hair and protein!

Wet Assessment Hair Breakage Break Down
  If your hair:

• (When Wet or Dry) Stretches slightly and returns to its original length without breaking, you are balanced! Stick with maintaining!
• (When Wet or Dry) Stretches a little more than normal then breaks, you need more protein in your regimen.
• (When Wet or Dry)Stretches, stretches, stretches with no significant breakage yet, add a bit more protein to your regimen.
• (Wet)- Feels weak, gummy, mushy, or limp, you need to add more protein to your regimen. (Wet or Dry) Experiences very little to no stretching, and simply snaps or breaks, you need to increase the moisture in your regimen.
• (Dry) Feels rough, tough, hard, dry, tangly, brittle, or any combination of those, you need more moisture in your regimen.
• Unsure? Err on the side of caution and give your hair moisture

    
            

http://www.blackhairscience.com/hair-breakage-101-protein-and-moisture/