Introduction Fat dissolving injections are a non-surgical cosmetic treatment designed to reduce small, stubborn fat pockets in areas like the chin, abdomen, arms, and flanks. Unlike diet and exercise, which shrink fat cells, these injections work by directly targeting and destroying them. Understanding how fat cells respond to these injections helps explain why results can be long-lasting and why swelling is a normal part of the process. What Happens When Fat Cells Are Injected? Fat dissolving injections are typically made from compounds that break down fat cell membranes. A well-known active ingredient used in medically studied treatments such as Kybella is deoxycholic acid, a substance naturally found in the body that helps absorb dietary fat. When injected into targeted fat deposits, the solution begins a controlled chemical reaction that affects fat cells directly.