Top 3 Best-Selling Weight-Loss Drugs to Watch in 2025

The weight-loss drug market is experiencing unprecedented growth, fueled by blockbuster GLP-1 and GIP/GLP-1 receptor agonists that are transforming obesity management. In 2024, a few key therapies dominated global sales and are expected to maintain strong momentum in 2025.

Here are the top three best-selling weight-loss drugs to watch in 2025 based on their financial performance and therapeutic impact.

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1. Wegovy (semaglutide)

Indication(s): Chronic weight management

Manufacturer(s): Novo Nordisk

2024 Sales (USD): $8.44 billion

2025 Outlook: Wegovy generated approximately $8.44 billion in 2024, while the full semaglutide portfolio — including Ozempic — exceeded $29 billion in sales. Wegovy continues to dominate the obesity drug category alongside its diabetes counterpart, Ozempic.

The company has faced challenges from supply shortages and increased competition, yet demand for Wegovy remains strong. The drug achieved about 200,000 weekly prescriptions in the US by late 2024, and 80% of insured patients paid $25 or less per fill through patient assistance programs.

Persistence data indicate that over 70% of US patients remain on weight loss drugs like Wegovy and Eli Lilly’s Zepbound after one year — double the rate seen early in its launch era.

In March 2024, Wegovy became the first obesity medication approved to reduce cardiovascular risk, cutting major adverse cardiovascular events (MACE) by 20% in high-risk adults.

Despite supply shortages and pricing challenges, Novo scaled up manufacturing and expanded insurance coverage. However, recent US performance has plateaued amid growing competition from players like Zepbound and compounded copycat issues.

2. Zepbound (tirzepatide)

Indication(s): Chronic weight management and obstructive sleep apnea

Manufacturer(s): Eli Lilly

2024 Sales (USD): $4.93 billion

2025 Outlook: Zepbound, Eli Lilly’s branded tirzepatide therapy for obesity, made a powerful entrance into the market last year. In its first full year (2024), Zepbound generated approximately $4.9 billion in global sales, with $1.9 billion recorded in Q4 alone — an 11-fold increase from the same quarter in 2023. Its dual GIP/GLP‑1 mechanism delivers impressive average weight loss of around 20%, outpacing many competitors.

To meet demand for its GLP-1 products, Zepbound and diabetes counterpart Mounjaro, Lilly continues to scale up manufacturing capacity, boosting production facilities in Indiana and North Carolina, to meet “unbelievable demand,” according to Lilly CEO David Ricks. It raised its annual profit forecast by $3 billion after Zepbound sales crossed the $1 billion mark in a single quarter.

Despite some formulary exclusions, such as by CVS Caremark affecting around 200,000 patients, Lilly adds roughly 500,000 new users each month, underpinning its dominant ~60% market share over Novo in the obesity drug segment.

3. Saxenda (liraglutide)

Indication(s): Chronic weight management

Manufacturer(s): Novo Nordisk

2024 Sales (USD): $1.01 billion

2025 Outlook: While increasingly overshadowed by newer, next-gen GLP-1s like Wegovy and Zepbound, Saxenda, approved for weight loss since 2014, remains a major revenue contributor, particularly in regions where Wegovy access is limited. Saxenda generated an estimated $1.01 billion (DKK 6.94 billion) in global revenue in 2024, with approximately $345 million in sales coming from the US. These figures reflect a slight decline in global share as next-gen, more potent GLP-1 and GIP/GLP-1 therapies, such as Wegovy and Zepbound, have entered the market.

Nevertheless, Saxenda continues to be a significant contributor to Novo’s overall obesity care business. In 2024, combined sales from Saxenda and Wegovy rose 57% year-over-year to DKK 65.1 billion (around $9.5 billion), accounting for nearly one-quarter of Novo Nordisk’s total revenue.

Honorable Mention: Mounjaro (tirzepatide)

Indication(s): Type 2 diabetes, chronic weight management

Manufacturer(s): Eli Lilly

2024 Sales (USD): $11.54 billion

2025 Outlook: While Mounjaro itself is not approved for weight loss, it drove significant off-label use before Zepbound’s launch and helped set the stage for the obesity-focused branding strategy that now powers Lilly’s market dominance. In 2024, sales skyrocketed from less than $500 million in its first year to $11.5 billion. Analysts project continued strong growth into 2025, supported by expanded manufacturing.