Skip to navigationSkip to main contentSkip to right columnADVERTISEMENTProsper Junior Bakiny, The Motley FoolThu, September 3, 2026 at 8:20 PM GMT+2 5 min readEli Lilly (NYSE:LLY) has achieved impressive returns in recent years, driven by soaring demand for tirzepatide, a medicine sold as Mounjaro for diabetes and Zepbound (in certain markets) for obesity. Tirzepatide has reached an amazing milestone: It has become the world's best-selling compound, despite being launched only about four years ago.That all sounds exciting, but considering tirzepatide accounted for 65% of Eli Lilly's revenue in the second quarter, what happens when competition in the GLP-1 market heats up, and many new therapies enter the fray? That's a real risk to monitor, but Eli Lilly is also aware of it and is working diligently to mitigate it.Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »The drugmaker recently posted clinical trial results suggesting tirzepatide may still have a significant growth runway, even as it faces increased competition.Image source: The Motley Fool.Tirzepatide impresses againEli Lilly ran a pair of phase 3b studies that enrolled patients with moderate-to-severe plaque psoriasis or active psoriatic arthritis who were also obese. These trials compared the efficacy of tirzepatide combined with Eli Lilly's Taltz, an immunosuppressant, versus taking Taltz alone. The results were highly instructive. For instance, 30.6% of patients with plaque psoriasis taking tirzepatide and Taltz achieved 100% skin clearance and at least 10% weight loss, compared to just 4.4% of those taking Taltz alone after 52 weeksAlso, 39.2% of patients with active psoriatic arthritis had achieved at least a 50% improvement in symptoms and at least 10% weight loss, compared with 1.7% of those taking only Taltz at week 52. There were other benefits of the combined therapy approach. Patients achieved greater improvements in glucose, cholesterol, BMI (Body Mass Index), and other important metabolic metrics when taking both tirzepatide and Taltz.Beyond diabetes and weight lossThe results of these clinical trials could have meaningful implications for tirzepatide. Let's consider two potential positive consequences. First, the medicine should continue expanding beyond its core markets of diabetes and weight management. It is also approved for obstructive sleep apnea, and it may eventually win label expansions across autoimmune disorders.Terms and Privacy PolicyEU DSA contactPrivacy & Cookie SettingsMore Info