How long do I have to wait to get a revision on facial fat transfer?

It depends a bit on what the concern is, so it's tough to say without more details or seeing pictures. I typically would advise waiting until you are at least 6 months out to make sure that it has fully settled before repeat grafting or attempting to remove any unfavorable graft.

Is the minimum time to wait, but 6 months is probably better, especially if the harvest sites will be the same.

It has been our experience with over 25 years of facial fat tranfers, that it takes 8-12 months for fat grafts to take and mature; in same cases even longer. You may see some, hopefuly better, changes coming in few months. In the meantime in person consultation, second opinion, with a board certified plastic surgeon(s), with good reputation in facial fat grafting, is recommended. Good luck.

Generally speaking most plastic surgeons, ask patients to wait six months before doing revision surgery. Often waiting longer is in everybody’s benefit.
Adding context to your question, would help give a more useful answer.
I generally steer people away from facial fat transfer, because the procedure is inherently extremely difficult with the long steep learning curve. Facial fat transfer is inherently, unpredictable and precise, and can be unforgiving. Using fillers on the other hand is quite the opposite. Fillers are precise, predictable, and forgiving if patients don’t like the outcome.
Removing a previously grafted fat in the face can be challenging and difficult.
Best,
Mats Hagstrom, MD