Weight, more than 40 bounds in 24 weeks. nearly 60 pounds in 48 weeks. i started losing weight within about a month of being on the drug. reporter: jacynthia jesse was part of the trial. and while some patients were given a placebo she believes she was given retatrutide itself. i have to say it was life-changing, to lose almost 60 pounds, especially someone, again, almost 300 pounds. reporter: testing is in its early stages. a submission for fda approval is years away. but eli lilly is hopeful it will get approval for a different drug this year. the weight loss version of its approved diabetes medicine mounjaro. there are analysts who say it will be the most lucrative drug ever made. hyperbole? probably, yes. i think at lilly we try not to focus to go on which drugs are going to be really big sellers. what we try to focus on is are we making medicines that treat a