There are different reasons why people lips could become dark, some could be natural while others may be induced. Lip hyperpigmentation is the major cause of dark lips. Healthline made available the different causes of dark lips.
1. Excessive exposure to the sun.
2. Low intake of water

3. Smoking:

This is a major reason why people lips get dark. When you keep smoking, the blood flow to your lips will reduce. Also, tar and nicotine present in cigarettes causes uneven pigmentation of the lips, thereby making them dark.

4. Excessive consumption of caffeine.


5. Allergic reactions to lipstick and toothpaste.

6. Frequent sucking of your lips.

7. Anemia.
8. Vitamin deficiency.

9. Chemotherapy
Healthline also made available the different home remedies that can help to lighten your lips.

Below are the home remedies.

1. Lemon.

Cut your lemon and extract the juice from it. Apply the juice to your lips at night and allow it to stay till morning. Rinse it off with cold water in the morning.

2. Lemon and sugar

Cut your lemon into equal parts and dip one part of it into the sugar. Use the lemon to scrub your lips. Allow the content to stay overnight and wash it out the next morning.

3. Lime.

Mix your lime juice with one tea spoon of honey and glycerin. Rub the mixture on your lips and allow it to stay overnight. Wash it out with cold water the next morning.

4.Turmeric

Mix your tumeric powder with one tablespoon of milk. Rub the mixture on your lips and allow it to stay for about five minutes. Ensure you rinse your lips with cold water after five minutes. In order to moisten your lips, you can apply a suitable lip moisturizer.

5. Aloe vera gel.

Apply aloe vera gel to your lips once a day. Endeavor to rinse the gel off immediately it dries off.