By Amanda Frost, PhD
Vice President, Research, PCMA

Did you know: the original patent for semaglutide – better known as Ozempic – should have expired this year.

Today, incredible hope for human health rests in drugs like semaglutide. But they highlight the tension between breakthroughs in medicine and access to these promising therapies. They also reveal the lengths drugmakers will go to block competition and keep prices high.

Let’s dive into the interesting class of GLP-1s.

GLP-1s, or glucagon-like peptide-1 receptor agonists, are generally approved to treat Type 2 diabetes, while some are approved for weight loss. While there have been new entrants to the handful of drugs in this class, the class itself is actually not new: the first, Byetta, received FDA approval in 2005. However, there are two drugs that dominate not just the news cycle, but seemingly all of popular culture: semaglutide – same drug, three brand names: Ozempic, Rybelsus, and Wegovy – and tirzepatide, a single drug marketed under the brand names of Mounjaro and Zepbound.

Someone Is Making A Killing

Nearly 10 million Americans in 2025 – almost double the number in 2023 – filled 32.8 million prescriptions for GLP-1s. According to IQVIA, total spending on the GLP-1 drug class in 2025 was $53 billion, or 9% of the total dollars spent on prescription drugs. This is a lot of money, and most of it went to two drug companies for two drugs: Novo Nordisk (semaglutide) and Eli Lilly (tirzepatide). Novo did approximately $22 billion in net U.S. sales of semaglutide in 2025, while Eli Lilly did a whopping $27 billion for tirzepatide.

This is the reward for innovation. Indeed, the U.S. patent system is designed to allow a brand name innovator drug an exclusivity period as a prize for the investment required to develop it.

When that exclusivity period ends, however, generic versions are expected to come to market and lower the costs for that drug significantly. Too often, the system doesn’t work and these exclusivity periods for brand name drugs go on for years longer than they should. This is because drug manufacturers have become adept at manipulating the patent system and blocking competitor generic and biosimilar products from coming to market.  GLP-1s are a prime example. Novo Nordisk has already filed 320 patent applications related to semaglutide, and Eli Lilly has filed 53 related to tirzepatide, all trying to block affordable generics for as long as possible. These create patent thickets through layers of duplicative and often meaningless patents.

Both manufacturers are heavily invested in their GLP-1; sales of their one compound comprise the vast majority of their total U.S. net revenues. Sales of semaglutide made up 86% of Novo’s total U.S. net revenue in 2025, while tirzepatide was 62% of Lily’s U.S. revenue.

It echoes the dominance of the blockbuster arthritis drug Humira. In 2022, the year before biosimilar versions of Humira finally hit the U.S. market after enjoying 20 years of exclusivity in the U.S., AbbVie’s U.S. net revenues from it were $18 billion (comprising 41% of their total U.S. net revenues). By 2025, AbbVie made just $3 billion in U.S. net revenues from Humira, or 7% of their total U.S. net revenue. A lot is at stake for these drugmakers when a patent is set to expire.

$50 Billion Is Just the Beginning  

Even average predictions expect the GLP-1 market to be nearly $200 billion annually by 2030, and bullish predictions are as high as $470 billion. One reason the market will continue to grow is the expansion of coverage in government programs. July 1, 2026, the Centers for Medicare & Medicaid Services (CMS) began the Medicare GLP-1 Bridge, a new, temporary GLP-1 coverage program for eligible Medicare beneficiaries. At least 4 million beneficiaries are likely eligible for the program, gaining GLP-1 coverage for the first time. Novo and Lilly could see an additional up to $10 billion annually.

One thing is clear, these two companies have a lot to protect and a lot to lose. And make no mistake, they are worried. The original patent for the compound semaglutide technically expired this year (March 20, 2026), although extensions and additional patents mean the U.S. will not soon see generics. The exclusivity periods for both semaglutide and tirzepatide will keep generic versions off the market until possibly the 2040s, thanks to manipulations of the patent system by both companies. But the development pipeline for similar weight loss and antidiabetic drugs is packed with would-be competitors, consisting of over 135 potential drugs from 60 companies. Huge profits plus waves of new competitors creates incentives for Lilly and Novo to protect their current products’ U.S. market share for as long as possible.

Competition Will Spur Lower Costs for American Families 

Drug companies with blockbuster brand drugs protect their market share with anticompetitive tactics designed to do two important things: extend the time they enjoy market exclusivity and block cheaper competitor products. Once cheaper competitor products arrive on the scene, revenues for a previously exclusive blockbuster brand drug sink like a rock. Humira revenues fell 500% in just three years after the market entrance of biosimilar competitors. And given the share of their revenues coming from a single compound, this is a situation that Novo and Lilly want to avoid for as long as possible. After reaping in billions, yes, they will make less money when the patents expire, but American patients, employers, and taxpayers will also be able to access more and cheaper options. But for now, the abuse of the patent system keeps costs for these drugs sky high. Competition is what brings prices down, and that’s being artificially blocked.

UP NEXT: What North American country already has generic Ozempic and why doesn’t the U.S.?

Read my next blog to find out…