Dark, dry armpits are definitely stained due to irritation caused by frequent shaving or friction resulting from rubbing with a sweater or blouse. Sweating and the use of deodorants and antiperspirants also contribute to less charming underarms. A dose of loving and tender care that includes shaving and proper removal of dead dry skin cells will usually do the job. Be patient and persistent, and do not expect beautiful armpits overnight.
Exfoliate your armpits weekly to remove dead and dry skin cells. Rub your armpits gently for two or three minutes with a mild, unscented body wash and a washcloth or mesh. You can also use a soft commercial scrub or brush.
Apply a moisturizing shave gel on the armpits before shaving, as it is thick and will adhere to the skin reducing friction. Never dry skin.
Shave underarms before going to bed at night. This will give the skin time to recover before you bathe and apply deodorant or antiperspirant the next morning.
Rinse your razor after each use and then store it in a dry and ventilated place. Replace your razor blades every four or five shaves because a dull blade is less effective and can cause folliculitis.
Apply an over-the-counter bleaching cream that contains hydroquinone twice a day if your armpits are dark. Wash and dry your hands and underarms, and then rub the cream in the dark areas according to the instructions on the label. Apply a mild moisturizer after using the cream, and use a sunscreen with an SPF of at least 15 before going outdoors.
Wear a soft cotton T-shirt under the sweaty sweaters to reduce the friction caused by dark, rough underarms.