What gives the hair the majority of its strength and elasticity?

The majority of hair's strength and elasticity come from keratin, a fibrous protein that forms the structural core of hair strands. Keratin's unique molecular structure provides resilience and flexibility, allowing hair to withstand various forms of stress. Additionally, the hair's cuticle, a protective outer layer, plays a role in maintaining its integrity and preventing damage, further contributing to its overall strength and elasticity.