Thank you for your question about removing underarm sagging skin in a non-surgical fashion. That is undoubtedly a multimillion-dollar question. In my experience, there is no definitive way to get rid of excess underarm hanging skin in a non-surgical fashion. There are modalities like radiofrequency and perhaps the Morpheus8 treatments. These treatments are modest at best when it comes to tightening underarm skin. Hopefully, there will be machines like transdermal ultrasound, which will help to melt the fat. Another technique you can consider would be cool sculpting. This is a non-invasive treatment that will help to remove the fat in the arms. I hope my answer helps to describe how to tighten loose hanging skin from the underarms. I specialize in arm lifts. I hope that I have answered your questions regarding the arm reduction. If you have any more questions regarding the arm lift, arm reduction, brachioplasty or arm crease fat grafting, please contact my office. Since a brachioplasty or arm lift surgery is a difficult procedure, please seek an experienced, board certified plastic surgeon with significant experience performing these types of arm lifts. Do your research. Make sure your chosen plastic surgeon has performed at least 100 arm lifts. Make sure they have the before and after pictures to prove it. Carefully examine their before and after pictures and check their reviews on RealSelf. Sincerely, Dr. Katzen. (“Verified” Plastic Surgeon, President of the American Society of Bariatric Plastic Surgeons, certified by the American Board of Plastic Surgery, Fellow of the International Society of Aesthetic Plastic Surgery, American College of Surgery, International College of Surgery, and American Board of Metabolic and Bariatric Surgery, and member of the American Society of Plastic Surgery, American Academy of Cosmetic Surgery and RealSelf Hall of Fame.)