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Darkened lips are caused by an overproduction of melanin. Smoking, certain medications and diet can contribute to an increase of melanin. Additionally, lipsticks, allergies, dehydration and sun exposure can cause lips to darken. However, there are many ways to naturally lighten your lip color.

Exfoliate and Moisturize

Remove the top layer of skin from your lips by rubbing gently with a damp washcloth or soft toothbrush. Smooth a layer of petroleum, cocoa butter, shea butter or other natural moisturizer across your lips at least five times a day, including mornings and evenings before bed.

Coffee, Tea and Nicotine

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Coffee, tea and nicotine will stain your teeth and lips. The nicotine in cigarettes increases melanin production in the body -- so quit or reduce the amount of cigarettes you smoke, and you'll reduce the darkening effects on your lips. Coffee and tea stain the lips when consumed in large quantities. Restrict consumption of these beverages to help lighten lip color. Instead, drink six to eight glasses of water daily to hydrate your skin.

Lemon Juice

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The citric acid found in lemons is very effective for lightening the skin. Apply the juice to your lips by rubbing a finger or q-tip dipped in lemon juice over the lips -- or by rubbing a freshly cut slice of lemon over the lips. Mix with honey for sweet tasting and effective lip bleaching. Honey contains an enzyme called glucose oxidase that produces hydrogen peroxide, a bleaching agent, when diluted. Apply a top layer of moisturizer to seal-in the juice. Do this twice daily for several weeks to lighten your lips.

Almond Oil

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Almond oil is an easy and pleasant way to lighten and add moisture to dark lips. There are several ways to apply almond to your lips. Finely crush two fresh almonds and mix with 1 tsp. honey, milk or shea butter. Almond powder or almond oil mixed with these ingredients is equally effective. Apply to lips. Leave on for at least 30 minutes. The mixture may be left on overnight. Continue for several weeks until lip color lightens.

Milk and Honey

Raw milk works well to lighten your lips, either alone or mixed with almonds or honey. Mix 2 tbsp. milk with 2 tbsp. honey or almond oil. Apply this mixture daily to your lips and leave on for at least 30 minutes.

Aloe Vera

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Aloe vera is a known curative with skin bleaching properties. Aloe also moisturizes the skin. Apply fresh aloe or aloe vera gel to your lips for a minimum of 15 minutes per day. Results are often noticed within one week, although this will vary according to the individual. Continue use until optimal results are reached.