New Delhi, July 3 -- NEW YORK - The woman had injected the vial herself. She was 72 and had bought retatrutide based on what she had read online about its clinical trial results. When she developed severe skin irritation, she did not know that the substance she had used was not approved by the Food and Drug Administration, or that no approved version even exists. She found out the same day a CBS News correspondent walked into a Brooklyn convenience store called Mr. Green and purchased a vial of the same compound for $95, with no prescription, no identification check, and no questions asked.

Retatrutide is an experimental weight-loss drug that Eli Lilly is developing for obesity and type 2 diabetes. It is currently in clinical trials. It ...