Try it when: You’re battling breakouts.
How it works: Tea-tree oil has antimicrobial properties and works to help minimize the bacteria responsible for pimples, says Howard Sobel, a New York City cosmetic dermatologist. Mix 5 drops in 4 tablespoons of aloe vera gel and apply as a toner after cleansing, says Harding.
Good to know: Tea-tree oil can also help with dandruff. A study showed that people who used a shampoo with 5 percent tea-tree oil reported a 41 percent reduction in flakes. Add 1 drop to a dollop of your own shampoo before sudsing up.