The results from your Kybella injections will not be noticeable immediately. It can take a few weeks or months for the full effects to be apparent. While the fat cells in this area are permanently destroyed by Kybella and will not regrow, the remaining fat cells can expand with weight gain. Keeping a healthy diet and lifestyle to maintain your current weight is essential, as weight gain can result in the growth of the fat cells underneath the chin and cause the reformation of submental fullness. Our New York, NY, area dermatologist will talk to you about the maintenance needed during your initial consultation appointment.