Hello, Dark spots on your lips is due to nutritional deficiency, sun damage, certain medical conditions also cause it. Avoid direct exposure to sunlight. Take water and fluids in adequate quantity. Change your toothpaste as a precaution, use herbal toothpaste. Limit caffeine intake. Sometimes, excess iron can also cause lip darkening. Take home-made food rich in vitamin D or you can also take supplements. Avoid getting dehydrated. dehydration cause chapped lips, skin, scabs and scars can cause changes in the lip color. Yes, apple cider has natural skin lightening and brightening properties. For lips you should use only after diluting it with water. Massage gently and then rinse with water after a few minutes. It will help to remove the dead skin cells. Apple cider helps to remove dark spots and hyperpigmentation as it contains ingredients like acetic acid, amino acid, mineral salts, etc. Avoid intake of excess iron in food. Avoid make up, do not apply lipsticks for a couple of days. Get clinically examined by a GP or a Dermatologist. Get hormone tests done, also get blood tests done to check Hb%, or any other pathology that is causing symptoms. It should go away with healthy diet and apple cider. If not, then consult a dermatologist. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician