GLP-1 and the obesity drug pipeline

• ClinicalTrials.gov lists 1,963 ¹ interventional studies of GLP-1 receptor agonists and GLP-1-based multi-agonists; 600 ² of them are recruiting or otherwise active, and 535 ³ are registered as Phase 3.
• 798 ⁴ of these studies started between January 2023 and September 2026. 378 ⁵ of them have a US site and 178 ⁶ a site in China.
• Semaglutide alone accounts for 365 ⁷ of the studies started since 2023, and tirzepatide for 184 ⁸.
• Beyond obesity (468 ⁹ studies since 2023) and type 2 diabetes (228 ¹⁰), the largest new clusters are cardiovascular disease (73 ¹¹), MASH (33 ¹²) and alcohol or substance use (31 ¹³).

New incretin studies rose from 66 ¹⁴ in 2020 to 101 ¹⁵ in 2021 and 223 ¹⁶ in 2025. The growth was steady rather than a single spike: 142 ¹⁷ studies started in 2023 and 191 ¹⁸ in 2024.

The United States remains the main site country. Studies with a US site went from 20 ¹⁹ in 2020 to 107 ²⁰ in 2025. Studies with a China site went from 16 ²¹ to 54 ²² over the same years. Much of the Chinese activity comes from domestic developers such as Innovent (mazdutide) and Sciwind (ecnoglutide), which run most of their trials at home.

Spending follows the trials. IQVIA estimates that GIP and GLP-1 agonists approved for obesity added $9.6 billion to US medicine spending growth in 2025 ²³.

Novo Nordisk and Eli Lilly dominate the registry. Semaglutide was named in 365 ⁷ studies started since January 2023 and tirzepatide in 184 ⁸. Both numbers include many academic studies that use approved products as tools, which is itself a sign of how embedded the class has become.

The next generation is already large enough to matter. CagriSema and cagrilintide appear in 41 ³³ new studies, oral orforglipron in 39 ³⁴, Innovent's mazdutide in 31 ³⁵, the triple agonist retatrutide in 25 ³⁶, Amgen's monthly antibody-peptide conjugate MariTide in 25 ³⁷ and Novo Nordisk's amylin/GLP-1 co-agonist amycretin in 22 ³⁸.

The mechanisms split into four camps: more receptors in one molecule (GIP, glucagon, amylin), oral small molecules, longer dosing intervals, and combinations that aim to preserve lean mass while cutting fat. A new entrant has to beat the leaders on at least one of these, with data, rather than simply match them.

Obesity or overweight was a listed condition in 468 ⁹ studies started since 2023 and type 2 diabetes in 228 ¹⁰. The long tail is where the new commercial arguments are being built.

Cardiovascular and heart-failure studies number 73 ¹¹, MASH 33 ¹² and chronic kidney disease 21 ³⁹. Alcohol and substance-use studies (31 ¹³) are mostly small academic trials, so industry has not yet committed there at scale. That gap is the clearest white space for a focused company, although it needs neuropsychiatric trial expertise rather than metabolic trial expertise.

Two approvals in the past year changed the competitive baseline. The FDA approved an oral tablet form of Wegovy (semaglutide) for weight management on 22 December 2025 (Drugs@FDA NDA 218316). It then approved Foundayo (orforglipron), the first oral small-molecule GLP-1 receptor agonist, on 1 April 2026 (Drugs@FDA NDA 220934).

Those join the injectables that built the market:

• Zepbound (tirzepatide) for weight management, approved 8 November 2023 (NDA 217806)
• Mounjaro (tirzepatide), 13 May 2022 (NDA 215866)
• Wegovy injection, 4 June 2021 (NDA 215256)
• Ozempic, 5 December 2017 (NDA 209637)

"Oral" is therefore no longer a differentiator on its own. An oral candidate now needs better tolerability, better liver safety or simpler manufacturing than the approved options. Pfizer's decision in April 2025 to stop danuglipron after a single case of potential drug-induced liver injury (Pfizer) is the reminder that a liver signal can end an oral small molecule late.

• Pick a differentiation axis you can prove in Phase 2. Candidates are lean-mass preservation, monthly or longer dosing, better gastrointestinal tolerability, and maintenance after weight loss. Each can be measured before Phase 3.
• Indications beyond obesity are where the next valuation step sits. Addiction, osteoarthritis pain, sleep apnoea and kidney disease still have few industry-sponsored trials.
• Plan for the cost of Phase 3. With 535 ³ Phase 3 studies already registered, pivotal trials in obesity are large and long. Most start-ups will need a partner before that stage.
• China is a practical early-development base. 178 ⁶ studies started since 2023 have a China site. Domestic data can support out-licensing if it includes head-to-head or mechanism data that global partners cannot get elsewhere.

Every trial count in this report is the totalCount returned by one query to the ClinicalTrials.gov API v2, retrieved on 26 September 2026. Each numbered citation opens a record whose source link re-runs that exact query. The track includes interventional studies whose interventions name a GLP-1 receptor agonist or a GLP-1-based multi-agonist, including development codes.

Site-country counts overlap: a study with sites in both the United States and China counts in both. Studies registered only in other registries, including China's drug trial platform and ChiCTR, are missing, so activity in China is understated. Asset counts match intervention names and codes, so they can miss studies registered under other identifiers and include investigator-initiated studies that use approved drugs. Approval dates come from Drugs@FDA records. Company programme status is based on public disclosures and should be checked against company announcements before it is relied on.