Q: What are Peptides for hair, and how do they help? A: Peptides are small chains of amino acids that act like the 'building blocks' of hair proteins (like keratin). In hair care, specific peptides are injected into the scalp (via mesotherapy) or applied through serums to improve blood circulation around the hair roots, reduce hair thinning, and make the actual anchoring of the hair strand stronger so it doesn’t fall out easily