minutes. repeat the treatment every day until the dark spots completely disappear.
a simple mixture of 1 teaspoon of lemon juice and 1 teaspoon of baking soda will also do its magic. rub the mixture on the dark spots and let it stay for around 5 minutes before you rinse it off. repeat the process 3 times a week until the dark spots are gone.
milk also has a similar effect. soak a sponge in milk and rub it on your armpits. let it stay for around 15 minutes and then rinse it off. you can repeat this treatment on a daily basis until the dark spots disappear. 