I had Radiesse injected in lips 15 months ago. Is filler still there? Is there a filler I could use to correct this? (photo)

It is possible to use a different type of filler in order to correct the issue. Something like Restylane or Juvederm might be better suited for your lips. 

In general, lip augmentation with Radiesse is "frowned upon" due to the potential for lumps and bumps. A filler made of hyaluronic acid (HA), such as Restylane or Juvederm, is better suited for the lips. These fillers can be used to even out deficiencies.  These last for about a year, whereas Radiesse lasts around one and a half to two years. If you choose to have an HA filler injected to even things out, beware that you may have some asymmetry due to the use of different fillers that were injected at different times.

Although Radiesse is a good product to add volume to the face, I do not recommend using it in the lips.  Radiesse is fairly firm and can cause irregularities in the lip.  I find the hyaluronic acid fillers (Juvederm, Restylane) work much better in the lips. You could use one of these to help smooth out any irregularity from the Radiesse.