What can go wrong with Renuva? I'm considering it to replace facial fat

Renuva is ideal for replacing fat loss anywhere in the body that naturally has fat, including the face. In your mid-twenties, you stop producing new fat cells — like you did when you were younger. If you are stressing and losing weight, that fat loss often shows on your face first.
Once injected, Renuva acts like a scaffold of sorts, that over the 3 - 6 months post treatment is replaced by your body's own fat.
However, since your concern is mostly in your under eye area, and since the fat pads on the face don't exist under they eyes, Renuva would not be ideal for you. For under eyes, it's best to use a filler, like Restylane or Juvederm. If you needed fat loss replaced in your cheeks, then Renuva would be the most natural options because the end result is your own actual fat.
Renuva is also ideal for people who don't want to undergo liposuction or anesthesia to harvest the fat needed for the fat transfer. Sometimes people don't have enough fat for transfer. In the case of a small amount of fat needed, Renuva is an ideal solution because it's comes in a box, like other injectables.
Best,Mats Hagstrom, MD