US GLP-1 prescriptions weaken as tirzepatide’s share rises to 57.9%
Citi’s tracking shows that total US GLP-1 prescriptions have turned negative year over year, while tirzepatide continues to gain share. Oral Wegovy now accounts for 35% of the brand’s prescriptions; the rollout of new oral products is occurring alongside a weakening overall market.
Original source：Citi ResearchFirst published on Unhidea：Original source date：
Key takeaway
The more pronounced shifts in GLP-1 are the concentration of prescription share in tirzepatide and the emergence of oral formulations, while the overall market remains in a phase of both year-over-year and week-over-week declines.
Total prescriptions are weakening, but how is the competitive landscape changing?
Based on the latest four weeks of data, Citi observed that total US GLP-1 prescriptions (TRx, including new and refill prescriptions) fell 2.0% year over year, compared with growth of 1.0% in its previous tracking; they also fell 0.4% week over week in the latest week. As oral options increased, overall prescription volume did not expand in tandem.
Eli Lilly’s tirzepatide accounts for 57.9% of total GLP-1 prescriptions, up from 52.1% a year earlier; Novo Nordisk’s semaglutide accounts for 35.9%. In the latest week, their prescription volumes rose 0.9% and fell 0.2% week over week, respectively, showing that tirzepatide’s share gain accompanied growth in its own prescriptions.
Does tirzepatide’s advantage come from weight loss or diabetes?
Both indications are contributing. In weight loss, Zepbound prescriptions rose 0.4% week over week in the latest week, giving it 62.2% of the market; Wegovy prescriptions fell 0.7%, with a share of 37.8%. The former’s share rose 0.3 percentage points that week, while the latter’s fell 0.3 percentage points.
The growth gap was larger in diabetes: Mounjaro prescriptions rose 1.4% week over week and Ozempic rose 0.3%, accounting for 40.6% and 25.6% of the GLP-1 diabetes prescription market, respectively. Although Ozempic prescriptions increased, its share still fell 0.1 percentage points, illustrating that absolute growth and an improved competitive position are not the same thing.
How much have oral drugs already changed the prescription mix?
Oral Wegovy now accounts for 35% of total Wegovy brand prescriptions, while the injectable accounts for 65%; the oral share was unchanged from the prior week. Citi sees this mix as a sign of patient preference for oral formulations. However, total brand prescriptions still fell 0.7% that week, so changes in the formulation mix and brand expansion need to be assessed separately.
Foundayo recorded approximately 58 thousand prescriptions in the latest week, down 4% week over week. Citi believes the holiday week may have affected this performance and also notes that IQVIA’s data collection may have gaps in telehealth channels. The single-week decline must therefore be assessed in light of both calendar effects and channel coverage.
Where does Citi see the drivers of a prescription rebound?
Citi expects changes in pricing and insurance coverage, Foundayo’s continued launch promotion, and the rollout of oral Wegovy to drive an increase in GLP-1 prescriptions. The business link is payment conditions and product availability: the former affects coverage for treatment, while the latter two expand oral options. Current data show that these drivers are still coexisting with a decline in total prescriptions.
