I know that the science says it can actually do anything but I can tell you that it is definitely doing something! I didn’t bother with it before because if was supposed to be snake oil- so to speak.
I am 57 and my once long thick lashes gave up the ghost a while back. I have used various lash serums over the years- some worked, some didn’t and they were expensive on the whole.
i smear the castor oil on my lashes before I go to bed- I don’t always remember each night.
in the mornings I recently thought I had forgotten to take my mascara off- then realised I hadn’t worn any. My lashes are noticeably darker and appear fuller.
You could say it was just the remnants of the oil BUR they are dark even if I don’t use if for a couple of days.
i wouldn’t say they are longer but they seem much fuller and darker. And castor oil is cheap as chips.