While it may not be able to eliminate them entirely, lemon juice can successfully lighten the appearance of dark spots on ones skin. Vitamin C, or L-ascorbic acid, is the reason that lemon juice has such as powerful effect.
When used on the skin, Vitamin C strips away the top layer of dead skin cells and exposes the lighter layer underneath, lightening the dark spots. Results are not instantaneous and lemon juice must be applied consistently for at least a month in order to see any results.
Individuals seeking to lighten their skin with lemon juice must also be cautious. Lemon juice is highly acidic and can irritate the skin and make it photosensitive. To avoid irritation, individuals should not apply lemon directly to the skin. They should instead mix it with ingredients, such as honey, water or aloe, which are gentler on the skin..