Thank you for your question regarding options to address flabby arms after significant weight loss. Congratulations on your incredible weight loss journey—losing 100 pounds is a remarkable accomplishment! To effectively tighten your arms after such a substantial weight loss, building muscle through weight training can help to some extent. However, even with dedicated weightlifting, it’s unlikely that you’ll be able to completely fill in the loose skin left after such a dramatic transformation. This is because skin laxity typically doesn’t shrink back fully after being stretched for an extended period, especially after significant weight loss. A brachioplasty (arm lift) is likely your best option for achieving a tighter, more contoured appearance. During this procedure, excess skin and fat are removed, and the remaining skin is tightened for a smoother, firmer look. While brachioplasty does leave scars, many patients find the improved contour and confidence it provides outweighs concerns about scarring. The appearance of your scars will depend on several factors, including your natural skin tone, genetics, and how your body heals. If you already have scars from other surgeries or injuries, they can provide a good indication of how you might heal. Over time, most scars fade significantly, and there are treatments—such as silicone sheets, scar creams, and laser therapy—that can further improve their appearance. In many cases, a tummy tuck and arm lift can be combined into a single procedure, reducing your overall recovery time. However, this decision will depend on your overall health, surgical plan, and the advice of your plastic surgeon. Ultimately, I recommend consulting with a board-certified plastic surgeon who can evaluate your unique anatomy and provide the best options tailored to your goals. You're already on an amazing journey—this next step can help you feel even more confident in your body! Sincerely, Dr. Katzen