i think CuteBeth may be on to something when she suggests internal lightening.
that won't just target your lips and can take a while to kick in depending on your dosage and metabolism.
i've had some success using Diana Stalder Glutathione Soap on my lips and topping it with Vasline once it dries.
it burns and may not be for everyone but i've seen some results!
you can use any soap you want that has lightening properties, not just Diana Stalder or not just Glutathione Soap.
Kojic Acid may work even better!
here's my lil guide, so if you have any questions about this method check here and i'll be able to answer you quicker!
http://www.askmehelpdesk.com/skin-li...ml#post1922859