Leave‑in keratin hair serum — a lightweight treatment designed to nourish, smooth and protect hair.Infused with keratin protein and other nourishing ingredients, this type of serum helps strengthen and smooth hair, reduce frizz, and add shine and manageability. Keratin serums coat hair strands to improve texture and protect against damage from styling or the environment.Smooths frizz and flyaways for a sleeker look.Adds shine and softness to dull or dry hair.Strengthens hair fibers by replenishing keratin protein.Helps make hair easier to comb and style.Apply a few drops to damp or dry hair, focusing on mid‑lengths to ends; no rinsing needed.