TRESemme Keratin Smooth weightless Silk Serum Get 3 days of weightlessly smooth hair with our pro-quality TRESemmé Keratin Smooth Silk Serum. Reach your shiny, smooth hair goals and transform your strands into a glossy style with intense shine, all while fighting frizz. This weightless serum also protects your hair from heat up to 450°, so you can protect and perfect your look. Our Keratin Smooth weightless system transforms frizzy hair into a smooth, sleek look for up to 72 hours.