Anti-obesity drugs become fourth-largest therapy class, IQVIA says

At the Academy of Managed Care Pharmacy annual meeting in Nashville, IQVIA said the anti-obesity market is now the fourth-largest therapy class, with a 4.6% share of the pharmaceutical market, and it is still growing ^[1].

Scott Biggs, director of supplier services at IQVIA, described how quickly the category moved up. "Throughout last year, I watched [the anti-obesity market] move into the No. 6 market position and then the No. 5 position, and it's now No. 4," he said. "A couple of years ago, we were not talking about Mounjaro or Zepbound" ^[1].

The category is worth nearly $42 billion, driven largely by GLP-1 medications available as injectables and orals ^[1]. GLP-1 therapies overall generated about $132 billion in 2025 sales, up 33.5% from 2024, while sales for the weight-loss indication alone rose 131% on a five-year compounded annual growth rate basis ^[1]. The total pharmaceutical market reached about $923 billion in 2025, up 12% ^[1]. Biggs said volume, not price, is driving that growth: price changes accounted for about 10% of growth and new product introductions about 7% ^[1].

Tirzepatide leads both categories. Mounjaro (tirzepatide) had 2025 sales of $39.1 billion, up 67.1%, making it the fastest-growing drug within diabetes ^[1]. Zepbound (tirzepatide) had $22.9 billion in sales, up 188.7%, making it the fastest-growing product within obesity ^[1]. Wegovy (semaglutide) followed with $18.6 billion, up 29.2% ^[1]. Three of the top five fastest-growing products are GLP-1 therapies, two of them indicated for obesity ^[1].

The pipeline holds about 190 obesity-related products, and IQVIA projects obesity therapies will contribute $100 billion in sales growth by 2029 ^[1]. Behind the anti-obesity class, immunology holds an 18.3% market share, antidiabetes 16.6% and oncologics 15.2% ^[1].

Distribution is heavily retail. Retail pharmacies account for 83% of total GLP-1 sales ^[1]. In the fourth quarter of 2025, about 41% of independent pharmacies did not dispense obesity-related GLP-1 medications, often citing profitability concerns tied to reimbursement rates ^[1].

Why it matters for patients

IQVIA's patient data suggest staying on treatment remains a challenge. In a study of about 8.6 million patients who filled GLP-1 prescriptions for diabetes at retail over one year, roughly 72% kept filling prescriptions in retail channels the following year ^[1]. In a similar analysis of 2.5 million patients using obesity medications, about 66.5% remained in retail channels after starting, and about 28% stopped treatment entirely within the first year ^[1]. IQVIA said the drop-off may reflect cost barriers, side effects or inconsistent insurance coverage ^[1]. Across new chronic therapies generally, only 29% of patients remain on treatment after one year ^[1].

Where a prescription gets filled may also matter. With most GLP-1 sales going through retail pharmacies, and a large share of independent pharmacies not dispensing obesity GLP-1s, the pharmacy a patient uses could affect how quickly a prescription is filled ^[1]. How often patients have to switch pharmacies to get a fill has not been reported.

IQVIA also pointed to direct-to-consumer programs and expanded indications, such as use in sleep apnea and metabolic conditions, as factors increasing access and shifting how the drugs are used. Those developments have led to increased Medicare and Medicaid coverage in certain cases, particularly when the drugs are prescribed for non-obesity indications ^[1].

What happens next

IQVIA projects obesity therapies will contribute $100 billion in sales growth by 2029 ^[1]. The company did not say when the roughly 190 pipeline products might reach the market, and no approval dates or price projections for those products were reported.