L’Oréal Professionnel Keratin Alpha Sleek Serum is a professional smoothing serum that provides a sleek finish and long‑lasting frizz control. The formula with 5% Keratin Sealer seals the hair fiber and forms a protective shield around the hair. As a result, the hair stays smoother, shinier and perfectly styled for longer. This serum protects against humidity and heat up to 230 °C, making it ideal for use with a blow‑dryer, straightener or curling iron.

  • Seals the hair fiber for long‑lasting smoothness
  • Protects against humidity and heat up to 230 °C
  • Visibly reduces frizz and improves manageability
  • Provides a sleek finish with intense shine