According to the Mayo Clinic website, melasma is a darkening of facial skin caused by a combination of ultraviolet radiation and increased hormones. Although the condition can affect anyone, pregnant women and women using birth control pills are prone to developing melasma, also called "the mask of pregnancy" or chloasma. Melasma usually causes dark spots above the lip area, on the forehead or on the cheeks. It can go away on its own but can also be difficult to get rid of. Prescription creams may help, but you can also treat melasma with natural remedies such as lemon juice and sweating.
See a dermatologist. You need to determine whether the dark spots on your skin are caused by melasma before you begin any home treatment.
Slice one lemon into four parts. Squeeze the juice of the lemon into a cup and take out any seeds.
Dip a small sponge into the lemon juice and apply it to the dark areas of your skin. The acid in the lemon juice will weaken the top layer of skin. Apply the juice once in the morning and once in the evening, directly onto clean skin, before putting on makeup or moisturizer. At night, wash your face before applying the lemon juice.
Repeat this process regularly for two weeks to see skin-lightening effects. If you go out in the sun, wear a sunscreen with at least 30 SPF under your makeup to keep the melasma from getting worse.
Drink plenty of water and exercise daily to promote sweating. Sweating helps your body remove excess toxins in your skin, which can help to reduce the darkening caused by melasma.