Applying lemon on the face is very good but can be bad If done without necessary precautions. Lemon has great antibacterial properties, it contains vitamin C and citric acid. These properties are very effective on the skin. For the face, lemon cures acne, rejuvenates and lightens the skin. Precautions to take are: 1. Lemon contains citric acid. In other words, can be very acidic especially for sensitive skin. It is best to dilute lemon with aloevera gel water, honey or other neutral profucts. 2. Lemon can lighten dark skin so it isn't advisable for a person with a darker skin tone.This may cause uneven skin tone. 3. It is best to use lemon at night or indoors to prevent direct reaction with rays of the sun. 4. If you experience skin reactions like redness, blemishes, you must stop application immediately.