Weightlifting and muscle-building exercises are the first treatment option to try for tightening underarm skin, according to the Daily Herald. If weightlifting doesn't produce satisfying results, it is possible to try nonsurgical options like laser treatments or skin removal surgery.
When loose skin has developed under the arms as a result of weight loss or age, it is possible to improve arm appearance with targeted exercises. Weightlifting can help bulk up muscle in the arms and chest which fills in the loose skin. Muscles to work out include the biceps, triceps, back and chest muscles with free weights, resistance bands and push ups, according to the Daily Herald.
Minimal sagging of the underarm skin may respond well to cool sculpting or laser treatments. Cool sculpting is a technique that destroys fat cells just under the skin using extreme cold. Over the course of weeks, the dead cells are moved from the area by the body, which effectively removes small fat pockets and love handles. Cool sculpting has not been approved specifically for use on the underarms, but some doctors may offer the procedure, according to CoolSculpting.
A final option for tightening very loose underarm skin may be a type of surgery called, brachioplasty, which is the removal of skin and fat from the upper arm. This procedure is more expensive and can leave behind a scar.