There are two things I use to put on my eyebrows that certainly made my eyebrows grow quickly and thick. One was coconut oil and the other was vitamin e. I was simply using them for the skin around my eyes but I noticed with both that I would go from plucking my eyebrows once a week to every 3 days. I also occasionally take vitamins a, c, d, and zinc but applying vitamin e certainly worked faster. When I don’t do it, I’m back to plucking my brows once a week and the hairs seem thinner when they grow in. I never tried it on my eyelashes but I’ve heard of people using it on their lashes.

My wife used to work in cosmetics. She recommends this one if a conditioner is enough to suit your purposes. But if you want a true serum, she recommends this one (or this one if you eventually increase your budget).