Pharmaceutical giant Eli Lilly (NYSE: LLY) has been the winner in the massive GLP-1 drug category, the class of medications that have proven extremely effective in lowering blood sugar levels and promoting weight loss. In fact, last year Lilly's medication -- called tirzepatide, which treats both type 2 diabetes and obesity -- became the best-selling drug on the planet. In doing so, it knocked Keytruda, the cancer immunotherapy drug made by Merck, off the throne. Tirzepatide is sold as Mounjaro for treati ...