What can help my small, thin lips?

Hyaluronic acid fillers are really the best option for lip augmentation. Any other options can lead to lumps and bumps. Fat is not predictable due to the movement of the mouth and lips.

Juvederm is normally used to "plump" up your lips and can last approximately six months.  It gives a natural appearance and is easy to go through.  Silcone can also be used, however you will need multiple sessions to achieve the look you want, because only a little at a time can be injected.  After you achieve a nice result with silicone, the result can be permanent.  Make an appointment with a board certified plastic surgeon to discuss your options.