Laser-assisted lipolysis works through selective photothermia, which occurs when laser-light energy is absorbed by fat and then converted into heat energy. The laser energy is transmitted to the adipocytes via the passage of a laser fiber. The adipocytes absorb the energy and rupture, yielding permanent volume reduction.

Laser-assisted lipolysis is a photo thermal process secondary to the absorption of laser energy by water which raises the temperature of the subcutaneous space and lower dermis. This causes contraction in all layers due to collagen remodeling.

The laser energy is delivered by thin fibers passed within the subcutaneous space. The main chromophore is water, which causes heating of the subcutaneous space and dermis. The lower dermis is heated to temperatures 5-8 degrees Centigrade higher than the surface of the skin. Tissue tightening through coagulation occurs at internal temperatures of 40 - 42 degrees Centigrade.