This is a dye, not a bleach, so you can naturally and safely lighten your eyebrows! If you have thick and light hair, you should leave it on for about 10-15 minutes. I left it on for 10 minutes because I don’t like having no eyebrows at all without makeup. When I do my makeup, I just brighten them up with brow mascara and it’s perfect! This product is expensive and famous for a reason. It’s super easy to use even for beginners... just open two kits, mix them well, and apply generously, and you’re done. It’s also very low irritation. However, the price is a bit high, so I’m not sure if I’ll repurchase. For those new to eyebrow dyeing and beginners, I highly recommend this product! There’s a tutorial by Giwoo on YouTube about how to dye eyebrows, so just follow that and you’re good to go.