Having tried various hair serums to keep my hair smooth and frizz-free, I found Kise Beauty's Keratin Serum to be a standout product. The inclusion of biotin and olive oil provides excellent nourishment, making my hair feel softer and shinier after just a few uses. What I appreciate most is its versatility; you can apply it before styling with a flat iron or blow dryer to protect hair from heat damage while ensuring a sleek look. The serum comes in a well-packaged box containing 12 individual 100ml bottles, which is convenient for both personal use and sharing with friends. I noticed that using a small, appropriate amount is key to avoiding any greasy residue while maximizing smoothness. Over time, my hair has shown less frizz and retains a natural shine throughout the day, which I attribute to the serum’s hydrating properties. If you often battle frizz or want to maintain a polished hairstyle, this keratin serum is definitely worth trying. It's especially suitable for those who use heat styling regularly and want added protection. Plus, it’s professional-grade, making it a reliable choice for both home and salon use.