Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain darkening of lips can be due to a number of factors but in case if you are using dyes to color or dye your beard and previously your goatee there is a possibility that the caustic substances in dye are leading to chemical burning of the lips gradually over the period of time. I would suggest you to limit up the use of dyes and when you apply also you can keep it away from lips.. You should also consult a Dermatologist and get evaluated so that a clinical examination can be done to rule out for other possible causes.. As of now you can start using Kojic acid,Glycolic acid and arbutin containing creams over the lips.. Apply Vitamin E gel.. Use natural bleaching and scrubbing agents like sprinkle a little salt over half a lemon and scrub your lips.. Avoid chemical cosmetics.. Limit sun exposure, smoking and drinking if you do.. Take Vitamin C supplements.. Drink plenty of water.. Hope this information helps.. Thanks and regards, Honey Nandwani Arora.