Eyelash Serum Make your own Eyelash Thickening Serum with Coconut Oil. It requires only 2 ingredients! Fractionated Coconut Oil and Lemon and Lavender essential oils. The fractionated coconut oil has a natural pulling action that draws out impurities and enters the eyelash follicles to stimulate regrowth. Adding 1 drop of Lemon enhances the oil’s cleansing and stimulating properties. Adding 1 drop of Lavender will nourish your lashes and follicles.