Once a relatively obscure class of drugs used for people with diabetes, GLP-1s have now shown an impressive ability to treat obesity, which affects over 100 million Americans. Horizons moderator William Brangham explores the great promise of the drugs and the potential concerns surrounding them with Dr. Jody Dushay, Dr. Rekha B. Kumar, Dr. Anna Lembke and Dr. Ziyad Al-Aly.