A friend was asking about acne the other day, so I did some research: Acne is caused by several contributing factors. Hormones are a major influence on acne. That’s why you don’t see acne before puberty. In women, birth control pills can either aggravate or improve acne. This probably depends on your response to the progestins in birth control pills. Bacteria contribute to acne - which is why either oral or topical antibiotics help. Greasy creams, perspiration, headbands and other things that can plug up pores make acne worse. Stress doesn’t help either. Surprisingly, what you eat is generally not a major contributing factor to developing acne.