Will more than 60% of oral Wegovy prescriptions through Q2 2026 go to patients without a prior injectable GLP-1 prescription in the preceding 12 months?

The Truveta 6-week data shows 36.1% confirmed new-to-GLP-1 plus ~24% undefined/other, totaling ~60% without confirmed prior injectable GLP-1 prescriptions. However, the 60% threshold sits precisely at this ambiguity boundary by design. Truveta explicitly warns switching rates will likely increase over time as patients cycle through prescriptions. Through Q2 2026 (a full 6 months of data accumulation), the switcher fraction should grow as payer coverage expands and injectable patients seek oral convenience. The early 6-week snapshot likely overstates the new-to-GLP-1 rate relative to the cumulative Q2 figure. I weight the temporal erosion of the new-patient share as the dominant factor, making this a near-coin-flip that slightly favors YES given the definitional advantage (compounded users count as non-cannibalized).

This run emphasizes the structural definitional advantage and the primary care prescribing signal. The market question specifically asks about 'prior injectable GLP-1 prescription' — compounded semaglutide users (1M+ patients) have no such prescription record. Even a modest conversion rate from compounding to oral Wegovy would substantially inflate the 'no prior Rx' category. The 92.8% primary care prescribing rate is striking evidence that oral Wegovy is reaching a genuinely different patient population than injectable Wegovy (which was predominantly specialty-prescribed). This demographic signal should persist and strengthen as primary care adoption deepens through Q2 2026. While switching will increase, the addressable market of needle-averse and primary-care-accessible patients is much larger than the existing injectable base, suggesting the new-patient inflow rate can outpace switching through Q2.

This run stress-tests the NO case by weighting temporal dynamics and selection bias more heavily. The 6-week Truveta snapshot captures the earliest adopters — disproportionately self-pay, highly motivated, and likely the most needle-averse segment of latent demand. As insurance coverage for oral Wegovy expands through Q1-Q2 2026, the patient mix should shift toward insured patients who already have injectable GLP-1 coverage and are switching for convenience, not cost. The ~24% undefined/other category may shrink as data matures and more records resolve to confirmed prior use. Furthermore, Novo management's own guidance language ('potential negative impact on injectable obesity medication category growth') implies they expect substantial cannibalization. If the steady-state switcher rate climbs from ~40% to ~50%+ and the undefined category resolves partly to switchers, cumulative through Q2 could fall below 60%.

The Truveta 6-week data anchors at 36.1% confirmed new-to-GLP-1 plus ~24% undefined/other, which arithmetically reaches ~60%. The market question's definition excludes compounded GLP-1 users from 'prior injectable prescription' by design, so compounding converts in the undefined/other bucket would count as non-cannibalized. Primary care prescribing at 92.8% further supports a genuinely different patient population. However, the 60% threshold sits precisely at the ambiguity boundary, making YES and NO nearly indistinguishable — a slight lean to YES based on definitional favorability to compounding converts.

Truveta researchers explicitly warn that switching patterns are expected to increase over time as patients cycle through prescription renewals and insurance coverage expands. The 6-week early adopter cohort is heavily selection-biased toward self-pay, motivated patients who are disproportionately new-to-GLP-1; steady-state adoption will include far more insurance-covered patients who previously used injectable Wegovy. Injectable Wegovy scripts are already declining from 280K to 270K, consistent with channel-shift cannibalization outpacing new demand. By Q2 2026, cumulative switching will have risen substantially above the 6-week snapshot, likely pushing the new-to-injectable-GLP-1 share well below the 60% threshold.

This question was deliberately constructed to sit at the ambiguity boundary of the Truveta data, making calibration extremely difficult. The undefined/other category (~24%) is the entire swing factor: if those patients are predominantly compounding converts or lapsed re-engagers, YES is likely; if they are data gaps masking prior injectable claims, NO is likely. Neither interpretation has strong external validation yet. The primary care prescribing signal (92.8%) is suggestive of market expansion but is not definitive, since injectable Wegovy patients also see primary care providers. The 1+ million compounded semaglutide patients represent a substantial pool of potential oral Wegovy adopters who would count as non-cannibalized, providing real upside to the expansion thesis, but the temporal trajectory of switching acceleration is the stronger counter-force through Q2 2026.

Conservative interpretation of Truveta: confirmed new-to-GLP-1 is 36.1%, and the ~24% undefined/other category likely contains more data gaps and misclassified switchers than genuine compounding converts. Even assuming half of undefined/other resolve as new-to-GLP-1, this yields ~48%, below the 60% threshold. Truveta's caveat that switching patterns may increase over time as prescriptions renew further depresses new-to-GLP-1 rates in the cumulative Q2 cohort. Primary care dominance is suggestive but not conclusive evidence of an entirely new patient base.

Central case balancing Truveta's direct measurement with primary care prescribing signal. Confirmed new-to-GLP-1 is 36.1%; assume undefined/other (~24%) splits 50/50 between compounding converts and data gaps, yielding ~48% from these categories. Primary care prescribing at 92.8% is strongly inconsistent with injectable prescribing patterns, suggesting oral is indeed reaching a different patient population. Combining direct data with the primary care channel shift pushes cumulative new-to-injectable rate to approximately 55-58% by Q2. Temporal uncertainty (switching may increase, but so may primary care-driven expansion) supports a middle estimate.

Optimistic case emphasizing primary care expansion and compounding market integration. Truveta's 92.8% primary care prescribing is a structural break from injectable distribution and strongly indicates oral Wegovy is accessing patients who never pursued injectable GLP-1. The 1M+ compounded GLP-1 market represents a hidden prior-use pool excluded from traditional prescription data; compounding converters count as new-to-injectable under the market definition. If undefined/other (~24%) resolves 60-70% toward new-to-GLP-1 (compounding converters and lapsed re-engagers), baseline becomes 36.1% + ~15% = 51%, which when weighted by primary care's expansion signal and modest injectable decline (suggesting limited true cannibalization) yields ~62-65% new-to-injectable by Q2 2026.