Use if: After so many chemical ingredients, now it is time for a more natural anti-acne treatment. Clinical studies show tea tree oil to be as effective as benzoyl peroxide, but with fewer side effects. It is a natural anti-inflammatory and anti-microbial ingredient, and has become a favorite of natural skin care followers. In addition, blemish-ridden skin can be incredibly sensitive, often as a result of chemical treatments. Thus, tea tree oil is far less irritating for anti-acne.