Concentration · one molecule's share of revenue
$12.8B of Lilly's $19.8B came from a single molecule (Mounjaro + Zepbound). Brilliant while it lasts — dangerous if it ever stumbles.
Source · 8-K · Item 2.02 — Selected Revenue Highlights (Mounjaro + Zepbound ÷ total revenue) · Q1 2026 · Filed Apr 30, 2026
From the 10-K · the concentration risk
Our anti-obesity medicines comprise a significant portion of our revenues, and barriers to reimbursable patient access impact our sales volumes, business, and results of operations.
↳ Lilly names it plainly: so much rides on these drugs that anything limiting who can get them covered — insurers, governments — directly dents the company.
Source · 10-K · Risk Factors — product concentration & patient access · FY2025 · Filed Feb 12, 2026
✦ Teach me
When the patent clock runs out
Every blockbuster drug eventually loses patent protection. When it does, cheaper copies can take most of its sales fast. And even before then, governments, insurers, and rivals push prices down — Lilly's realized prices already fell 13% this quarter.
Wall Street calls this
Patent cliff & pricing pressure
The bigger the single drug, the harder its eventual cliff — and the price erosion is already starting.
From the 10-K · loss of exclusivity
[Generic or biosimilar competition] can result in the loss of a significant portion of the branded product's revenue in a very short period of time.
↳ Plus a live rival: Novo Nordisk competes head-to-head in GLP-1, and government drug-pricing pressure is rising. The price declines this quarter are the early edge of that.
Source · 10-K · Risk Factors — loss of exclusivity & competition · FY2025 · Filed Feb 12, 2026