Lemon juice is a wonderful cure for acne! Freshly squeezed lemon juice can be applied topically and because it has an acidic pH will kill the bacteria on the skin. It is also a powerful antioxidant and exfoliant, thus it works for wrinkle prevention and treatment of scars. The skin on which lemon juice was applied should not be exposed to UV light (no tanning). Some people dilute the lemon juice, because it stings and the effects will be less potent in this case. Most people say they got used to the stinging sensation so there is no need to dilute it. Either way lemon juice will have great results (much faster if using non-diluted).
Lemon juice should only be applied upon proper cleansing of the skin, see the article Holistic Skin Care Tips.