2036, date not disclosed
Mounjaro expected to lose US exclusivity
Company guidance. Lilly 10-K: US compound patent expires 2036. Excludes Zepbound, the same molecule sold for obesity.
When does Mounjaro go off patent?
In the US, generics can launch from 2036. Mounjaro is sold by Eli Lilly. Lilly 10-K: US compound patent expires 2036. Excludes Zepbound, the same molecule sold for obesity.
Mounjaro'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 compound patent | Tirzepatide itself (also Zepbound) | 2036 |
| US data protection | FDA new-chemical exclusivity | 2027 |
| EU compound patent | Tirzepatide itself (Europe) | 2037 |
| Japan compound patent | Tirzepatide itself (Japan) | 2040 |
Generic makers can file to copy tirzepatide once US data protection ends in 2027, but the compound patent runs to 2036. In July 2026 Lilly said several companies had already filed applications challenging its patents, and that it intends to sue. The same patents protect Zepbound, the obesity brand, so the two products face the same date.
Sources: Lilly 10-K 2025 · Lilly 10-Q, Q2 2026
| Year | Worldwide | US | Growth |
|---|---|---|---|
| 2023 | $5.16B | $4.83B | – |
| 2024 | $11.54B | $8.95B | +124% |
| 2025 | $22.96B | $13.65B | +99% |
Worldwide net sales as reported, with the US share. Source: Lilly 10-K 2025
Filed with the FDA Lilly received notice in July 2026 that multiple generic companies had filed applications to copy Mounjaro and Zepbound before its patents expire, and said it intends to sue. Lilly does not name the filers; its US compound patent runs to 2036.
| 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 →
Mounjaro is 35% of Eli Lilly's 2025 revenue ($23.0B of $65.2B). With Trulicity, Jardiance, Taltz, Verzenio and Zepbound, 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. Mounjaro is highlighted.
Company guidance. Lilly 10-K: US compound patent expires 2036. Excludes Zepbound, the same molecule sold for obesity.
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