While the product is suitable for use on eyebrows, it's important to be aware that the kit includes instructions only for eyelashes, not brows. When applying the BOO-original professional kit to eyebrows, reduce the processing time by 3-4 minutes compared to the recommended lash time. For instance, if the suggested processing time for thick lashes is 13-14 minutes, adjust it to 10-11 minutes for thick brows. If you're using the BOO-Pure care system for brows, maintain the same timing as indicated in the lash guideline.