2036, date not disclosed
Zepbound expected to lose US exclusivity
Company guidance. Same molecule as Mounjaro (tirzepatide), sold for obesity. Lilly 10-K: US compound patent 2036.
When does Zepbound go off patent?
In the US, generics can launch from 2036. Zepbound is sold by Eli Lilly. Same molecule as Mounjaro (tirzepatide), sold for obesity. Lilly 10-K: US compound patent 2036.
Zepbound's US exclusivity date is based on company guidance. The date comes from the company's own filings or guidance. Secondary patents, new formulations or litigation can still move it. It is a peptide regulated as a drug rather than a biologic, so copies are generics. Peptides are harder to copy than typical pills, so generic uptake can be slower.
| Patent or protection | Covers | Expiry |
|---|---|---|
| US 9,474,780 | Tirzepatide itself and the drug product (also Mounjaro) | 13 May 2036 |
| FDA new-chemical exclusivity | Data protection for tirzepatide | 13 May 2027 |
| Seven later patents | The drug product and approved uses | 22 July 2039 |
Zepbound is tirzepatide, the same molecule as Mounjaro, so the two face the same date. Lilly puts US compound patent expiry at 2036 and data protection at 2027. In July 2026 Lilly said several generic makers had applied to copy tirzepatide before its patents expire, and that it intends to sue. Later patents on the pen and on uses run to July 2039.
Sources: FDA Orange Book data files · Lilly 10-K 2025 · Lilly 10-Q, Q2 2026
| Year | Lilly | US | Growth |
|---|---|---|---|
| 2023 | $0.18B | $0.18B | – |
| 2024 | $4.93B | $4.93B | +2699% |
| 2025 | $13.54B | $13.48B | +175% |
Zepbound launched in the US in late 2023; sales outside the US began in 2025. Net sales as reported, with the US share. Source: Lilly 10-K 2025
Filed with the FDA Filed together with Mounjaro: in July 2026 Lilly received notice that multiple generic companies had applied to copy the drug before its patents expire, and said it intends to sue. The filers are not named.
| Company (product) | Stage |
|---|---|
| Several generic makers (not named by Lilly) | Filed with the FDA Jul 2026 |
Checked October 2026. Sources: Lilly 10-Q, Q2 2026
Among past small-molecule drugs facing unrestricted generics, US sales in the first full year after copies arrived were a median 18% of the last full year before (range 0% to 48%, 10 drugs), and 6% by the third year (8 drugs). Where settlements limit generic volumes, as with Revlimid, the decline is slower. Every drug is different: settlements, how many copies launch, and pricing all change the curve. See the erosion benchmarks →
Zepbound is 21% of Eli Lilly's 2025 revenue ($13.5B of $65.2B). With Trulicity, Jardiance, Taltz, Verzenio and Mounjaro, the drugs tracked here add up to 82% of Eli Lilly's revenue losing US exclusivity by 2036.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Zepbound is highlighted.
Company guidance. Same molecule as Mounjaro (tirzepatide), sold for obesity. Lilly 10-K: US compound patent 2036.
Lilly received notice that multiple companies had applied to sell generic tirzepatide before its patents expire, and said it intends to sue. Its US compound patent runs to 2036. Lilly 10-Q, Q2 2026