Exfoliation can promote the growth of new skin cells, prevent the development of acne and pimples, and reduce the appearance of acne scars. Lemon juice is also known as a natural skin lightener, and so, it can be used to lighten or reduce the appearance of dark, discolored spots, and scars. It can also give a flawless and even complexion. However, this remedy works slowly, which means that it can take a few weeks, before you can notice any significant change.