Wow! I was apprehensive at first, but am so pleasantly surprised by this product! It took some effort to apply to my eyebrows, but the result was great! The color was subtle but enough to notice, my boyfriend noticed something "different" about my face but couldn't place it until I told him I darkened my brows. I left it on for just under two hours and I think I could have left it on a little longer to get some more color. It also smells AMAZING like a high-end perfume, thinking lancome or chanel. I only applied to areas of my brows that had hairs, I watched a youtube tutorial where someone went outside her brow hair line and it ended up looking a little funny. I think this is for people who want to darken brows, not fill in areas with no hair. It also came much faster than expected, especially coming from Korea. I got two little samples of face product and a cute little note. I'm definitely going to be buying more of this stuff.