Technology guide
Adipocyte apoptosis: programmed cell death triggered by cold
In cryolipolysis, cold does not destroy fat cells abruptly: it triggers their programmed death, known as apoptosis. This mechanism explains why results appear over a few weeks.
What is apoptosis?
Apoptosis is programmed cell death: the cell dismantles itself in an orderly way, without damaging neighbouring tissue. It contrasts with necrosis, a sudden death in which the cell bursts and triggers strong inflammation. In cryolipolysis, it is the controlled cooling of adipocytes that sets this process in motion.
Step one: lipid crystallisation
During the cold phase, the fats stored in the adipocyte crystallise. These crystals create mechanical stress and disrupt the cell's functioning, and the cell then activates its internal self-destruction signals.
Step two: fragmentation
In the hours that follow, enzymes called caspases cut up the cell's components. The adipocyte breaks down into small apoptotic bodies and displays a signal on its surface that marks it as a cell to be eliminated.
Step three: elimination
Macrophages, the immune system's clean-up cells, arrive in the area and absorb these fragments. The lipids they contain are then cleared via the lymphatic system and reintegrated into normal metabolism. This clean-up takes place over several weeks, which explains why results are gradual.
What your client may notice
Immediately after the session, redness and slight swelling are common, then fade. A slightly hardened or tender area may be felt in the first few weeks. Volume then decreases gradually, with a stabilised result at around 8 to 12 weeks according to the source.
Lasting results, on one condition
Eliminated adipocytes do not re-form. However, the remaining ones can grow larger if weight is gained: maintaining a stable weight is still necessary to preserve the result.