Leave-in serum ideal for flexible, curly looks This serum for curly hair is a curl-enhancing, leave-in treatment that creates bouncy, defined curls without weighing hair down. It smooths unruly curls while promoting lightness and bounce. Its light hold, frizz-fighting power, and easy workability make it the ideal curl serum, from loose waves to tighter curls. Free from parabens and added colourants.