Mounjaro's 2022 approval set a $1,023 list price and exclusivity running to 2027

The FDA approved Eli Lilly's tirzepatide, sold as Mounjaro, for adults with type 2 diabetes in May 2022 ^[3]. The approval set the clock on pricing and market exclusivity for a drug that has since become one of the highest-selling medicines in the United States ^[2][5].

Tirzepatide is a once-weekly injection and the first drug in its class to target both the GLP-1 and GIP receptors, an approach researchers describe as "twincretin" ^[3]. Eli Lilly developed it, and the FDA cleared it under the brand name Mounjaro in May 2022 ^[3]. In a price comparison of weight-loss and diabetes drugs, KFF lists Mounjaro at $1,023 per month in the United States for the 15 mg dose, based on data collected as of August 15, 2023 ^[1]. The same analysis lists the drug at $444 a month in the Netherlands and $319 in Japan ^[1].

Those are list prices, the sticker price before rebates and discounts. KFF notes that list prices are not necessarily the net prices insurers pay, because manufacturers provide rebates to insurers and coupons to patients ^[1]. For comparison, the same analysis lists Ozempic and Rybelsus at $936 a month in the US and Wegovy at $1,349 ^[1]. It also found the US had by far the highest obesity rate among the large, wealthy countries studied: 33.5% of adults, against a peer-country average of 17.1% ^[1].

The FDA's Orange Book listing for tirzepatide spells out the exclusivity periods tied to that first approval. New chemical entity exclusivity runs to May 13, 2027, and a "new product" exclusivity runs to November 8, 2026 ^[2]. Exclusivity covering labeling revisions based on clinical studies runs to October 18, 2027, and exclusivity tied to treatment of moderate to severe obstructive sleep apnea in adults with obesity runs to December 20, 2027 ^[2]. The same listing shows patents with expiration dates of May 13, 2036, and June 14 and July 22, 2039 ^[2]. Those listings do not disclose when, or whether, a competing version of tirzepatide would reach the US market.

Commercially, the launch was among the largest the industry has recorded. IQVIA reports that Mounjaro launched in 2022 and, nearly three years later, was selling around $3 billion a month, while Lilly's obesity brand Zepbound, launched in 2023, was on track to pass that figure ^[5]. IQVIA says Mounjaro and Zepbound are, along with Harvoni, the only products ever to top $5 billion in sales in their first 12 months, and that about 11 million unique patients in the US were using a GLP-1 drug as of the second quarter of 2025 ^[5].

Why it matters for patients

List price is the number that shows up in policy debates, insurance formularies and headlines, but it is not what every patient pays. Rebates and coupons can lower the amount, and KFF cautions that list prices may differ from net prices ^[1]. At the same time, KFF notes that Medicare is not allowed to cover weight-loss drugs under current law and that Medicaid coverage varies by state, so what a patient owes depends heavily on their plan ^[1]. The analysis says it remains to be seen what share of the cost of these drugs patients or insurers will ultimately bear ^[1].

Exclusivity dates also matter, because they shape how long tirzepatide can be sold without competing versions. The exclusivity and patent dates listed by the FDA run from 2026 into 2039, but what any of those dates mean for the availability or price of a competing product has not been disclosed ^[2].

Another practical point concerns what the drug is approved for. Mounjaro is an injectable prescription medicine for adults with type 2 diabetes, used with diet and exercise; Zepbound is approved for adults with obesity or excess weight plus a weight-related condition ^[4]. Lilly has said it does not supply tirzepatide to compounding pharmacies, med-spas or online sellers, that it is the only lawful supplier of FDA-approved tirzepatide medicines, and that neither brand is approved for people under 18 ^[4].

What happens next

The dated milestones listed by the FDA are the "new product" exclusivity on November 8, 2026, new chemical entity exclusivity on May 13, 2027, labeling-related exclusivity on October 18, 2027, and obstructive sleep apnea exclusivity on December 20, 2027, with listed patents extending to 2036 and 2039 ^[2]. Whether those dates lead to generic or competing tirzepatide products in the US, and at what prices, has not been reported.