>>40341984fat cells dont die on their own in practical terms. the only people ive ever heard say they do have never had to contend with them. they do have 2 methods of dying via external intervention however: apoptosis, and necrosis. apoptosis is where the cell is triggered to kill itself, releasing its contents in a controlled manner to be cleaned up by the lymphatic system. necrotic death involves uncontrolled cell rupture, results in far higher inflammatory signals, and takes longer to heal.
depending on the method, apoptosis can be more or less preferable. phosphatidyl choline injections are a common method of triggering apoptosis however its possible for cells to become resistant to them. cryolipolysis is another common apoptotic method of killing fat cells which exploits their heightened vulnerability to death from lower temperatures vs higher temperatures. there ere certain enzymes you can get in injectable solutions that also claim to trigger fat cell apoptosis.
aqualyx (deoxycholate solution) injections are a common method of destroying fat cells via necrotic methods. they are impossible for fat cells to resist damage from, but their necrotic method of action means they take between 1 and 2 months for swelling to go down from.