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How to dye your eyebrows with coffee
Combine the leftover coffee grounds and cocoa powder.
Add 2 tablespoons (21 g) of coffee grounds and 1 teaspoon (3 g) of cocoa powder to a small bowl. Mix the two ingredients well so they're fully combined.
Be sure to use caffeinated coffee grounds. Caffeinated coffee usually offers a richer color, and the caffeine is also thought to stimulate hair growth so it may help if your brows are sparse or patchy.