Our Castor Oil Dense Hair Serum contains castor oil. It promotes hair quality, prevents hair breakage, prevents split ends and strengthens hair from the roots. The way it works is simple:1. Take an appropriate amount of essential oil and gently brush the eyebrows . 2. Or take an appropriate amount of essential oil and apply it to the hair roots, and gently massage and absorb with your fingertips. 3. Use it daily for better results. And it can improve hair follicle problems and so on.