I have used castor oil on and off for many years, even back when I was a teen. It conditions my eyelashes and eyebrows, they look nourished and healthier. It does not however make them longer. I use it at nights then rinse in the morning. Surely, eyelashes look a bit fuller when I apply mascara after. It promotes healthy eyelashes and I would rather use this than some chemicals which have side effects. Same effect on eyebrows.