Scrub:
Mix 1tablespoon of brown sugar, 2 tablespoons  of raw honey, Half a lemon not lime please. Scrub your lips with it, rinse off with warm water then apply almond or olive oil. Repeat daily till you see results

OR

Rose petals:
Prepare paste from rose petals by adding butter to it.Apply the mixture on lips rose petals helps to lighten the dark lips try to make it twice in a week for better noticeable results.