Lilly reports a 60.1% US incretin market share

Eli Lilly reported first-quarter 2026 results on April 30 showing that its share of the US incretin market — the category that includes GLP-1 drugs for diabetes and obesity — reached 60.1% as of March 2026, up from roughly 45% a year earlier ^[2]. Total company revenue rose 56% to $19.8 billion, and Lilly raised its full-year revenue forecast to $82 billion to $85 billion ^[1].

The two tirzepatide brands drove most of that. Worldwide Mounjaro revenue rose 125% to $8.7 billion, split between $4.2 billion in the US (up 59%) and $4.4 billion outside the US, compared with $1.2 billion abroad a year earlier ^[1]. Lilly's earnings slides put Mounjaro's US share of the type 2 diabetes incretin segment near 51% ^[2].

For Zepbound, Lilly's press release said US revenue rose 79% to $4.1 billion from $2.3 billion a year earlier, while the revenue table lists $4,160 million and a summary of the slide deck describes $4.2 billion in US sales plus $26 million internationally, an 80% increase ^[1][2]. The sources round these figures slightly differently. Lilly's slides said Zepbound held more than 50% of the branded incretin obesity market by the first quarter ^[2].

Prices are falling as volume climbs

The growth came almost entirely from more prescriptions, not higher prices. Lilly said the 56% revenue increase reflected a 65% rise in volume, partly offset by a 13% decline from lower realized prices ^[1]. In the US specifically, volume rose 49% while realized prices fell 7%, a decline Lilly attributed primarily to Zepbound and its immunology drug Taltz ^[1]. The company pointed to "previously announced reductions in cash pay prices" for Zepbound as one reason revenue per prescription dropped, though a one-time accounting adjustment to rebate and discount estimates worked in the other direction ^[1]. The overall US incretin market grew 30% in the quarter, so Lilly's share gains came on top of a market that is still expanding ^[2].

Lilly also described the early US launch of Foundayo (orforglipron), the oral GLP-1 pill approved by the FDA during the quarter ^[1]. According to the slide summary, Foundayo reached broad retail availability by April 9, with more than 12 telehealth platforms carrying it and accounting for about 35% of launch volume ^[2]. More than 80% of Foundayo prescriptions went to people who had not used an incretin drug before, which Lilly read as evidence the pill is reaching new patients rather than pulling people off injections ^[2]. Commercial coverage was expected at two-thirds of major pharmacy benefit managers by mid-May, with Medicare access planned through a "GLP-1 Bridge" program starting July 1 and full consumer advertising beginning in the third quarter ^[2].

Why it matters for patients

Market share numbers are business metrics, not clinical ones, but they shape what patients encounter at the pharmacy counter. A company holding 60% of a category has more leverage in contract talks with insurers and PBMs, which can influence which drug sits on a formulary and which requires prior authorization or a step through another product first. The sources do not say how any specific plan will respond.

The pricing detail is the more immediate point. Lilly's own numbers show it is collecting less per unit than a year ago in the US, partly because of cash-pay price cuts it announced earlier ^[1]. That trend matters most to people paying without insurance coverage. The sources do not list current cash prices for any product.

The Foundayo data point about new patients is worth watching: if the pill mainly adds people to the category rather than shifting them from injections, overall demand — and pressure on supply and budgets — keeps rising ^[2].

What happens next

Lilly said Medicare access for Foundayo through its Bridge program is planned to begin July 1, with broader consumer promotion in the third quarter of 2026 ^[2]. The company expects Phase 3 data this year on retatrutide in obesity (TRIUMPH 1/2/3) and orforglipron in obstructive sleep apnea, plus regulatory decisions on tirzepatide for cardiovascular outcomes ^[2]. Lilly has scheduled an Investment Community Meeting for December 7, 2026 ^[1].