A friend of mine who recently came back from Australia told me about this natural acne treatment (it can be found in the States too, it's just better known over there): Tea tree oil.

Tea tree oil is a substance obtained from the destillation of the leaf of an Australian plant. It seems to be a very efficient acne treatment due to its antibacterial properties. There are many acne creams and gels for sale containing this substance, and you can buy them in pharmacies and stores selling health foods almost everywhere.

The good thing about this oil is that, even though it does not attack the root causes of acne, it is still very effective and has virtually no side effects ( like itching or irritation ). On the other hand, it may take a little longer for you to see results.