IPL (Intense Pulsed Light) affects the superficial layers of the skin and only penetrates deep enough to reach the roots of hair, but IPL does not penetrate deeply enough to dissolve fat. IPL is usefull for removal of hyperpigmentation, freckles, red spots and dilated vessels, and removal of hair (epilation).
IPL could cause skin burns if applied too aggressively. My experience is that it is difficult to overtreat with IPL due to the pain that is associated with the treatments in lighter skinned individuals. I recommend that dark skinned (Fitzpatrick types V and VI) individuals avoid IPL treatments because burns are much more likely in these individuals.
Fat loss occurs as a natural part of the aging process and can occur with dieting and weight loss as well. Other causes of fat loss in the face include malignant neoplasms, antiviral therapy for HIV, and other medications (decongestants, beta blockers, and diuretics).