One session lasts six months to a year. Change starts from two to three weeks and is clearest at eight to twelve weeks, because collagen builds up while the treated spots heal. Wide areas such as the abdomen or thighs are not covered in one go but worked through zone by zone.

Body Shurink uses ultrasound to place heat in dots in the deep layer, stimulating fat and the layer that supports it together. Onda uses microwaves to heat fat selectively, so it also addresses cellulite. If tightening is the goal Body Shurink suits; if the fat itself is the concern, Onda.

Downtime is mild, about one to three days. A tingling feeling can linger for a few days — that is a natural response as the spots heated in the deep layer heal. Drink plenty of water to help the body clear the fat broken down by the heat, and skip hard exercise for a week.