England dispenses over 390,000 GLP-1 items a month, nearly three times the 2021 figure. Scroll to watch what the class total hides.
Four molecules, one direction. Semaglutide and dulaglutide climb together; liraglutide, the oldest, drifts gently down, the ordinary retirement of a mature molecule.
A class-level forecast fits this period beautifully. That's the trap.
24,089 items in September. 14,780 in October. 7,518 by December. 1,049 by June 2025: a 97% collapse, most of it inside nine months.
Money that left one formulary line and reappeared on another. A model that only grows the class never sees this happen.
Effectively zero before February 2024. 73,147 items by month six. 215,103 by June 2025, past every incumbent, the largest GLP-1 in English primary care.
Uptake curves this steep exist. Assuming one for your asset is the expensive part; this is what the reference class actually looks like.
About 135,000 items a month by mid-2024, then sideways for a year while the class kept expanding around it.
In US Medicaid the same molecule is still growing and still the leader. Same drug, different system, different curve.
Tirzepatide 215k · semaglutide 127k · dulaglutide 48k · liraglutide 1k.
Neither number is visible from the other. If your budget impact model works at class level, it is averaging away the only thing that mattered.
Every line above is England's national prescribing data, read at molecule level in our data lake, the same engine that supplies launch analogues and switching evidence for budget impact and forecast models.
Read the full analysis Next story: One molecule, three prices