What 2025’s top-selling drugs, GLP-1 momentum, and five-year approval patterns reveal about competition
| KRW 548.1bn Keytruda – 2025 No. 1 | KRW 688.0bn Wegovy + Mounjaro | KRW 29.05tn 2025 Korea pharma market |
South Korea’s most commercially powerful drug story in 2025 was not that Keytruda remained No. 1. It was that two obesity medicines, Wegovy and Mounjaro, together generated more distribution sales than Keytruda by itself.
IQVIA distribution data analyzed by HIT News placed Keytruda at KRW 548.1 billion in 2025, followed by Wegovy at KRW 472.5 billion. Mounjaro, despite being on the Korean market for only about four months during 2025, reached KRW 215.5 billion and ranked fourth. Together, Wegovy and Mounjaro reached KRW 688.0 billion – a commercial signal large enough to sit above the country’s leading individual prescription medicine.
That shift matters because it is happening inside an already expanding pharmaceutical market. IQVIA figures cited in a 2026 Korean corporate filing put South Korea’s pharmaceutical market at KRW 29.05 trillion in 2025, up 8.3% from 2024 and roughly 32% above the 2021 level. The opportunity is therefore not just about a growing market; it is about a changing mix of therapies, with oncology still dominant but metabolic drugs rapidly claiming commercial space.
The 2025 revenue leaderboard: oncology still leads, but GLP-1 changed the hierarchy
The table below uses a common 2025 metric: IQVIA prescription-medicine distribution sales by product name, with strengths and distribution channels combined, as reported by HIT News. These figures are best interpreted as a market-sales proxy, not as audited manufacturer net revenue.
| Rank | Drug | Active ingredient | Company | Therapy area | 2025 sales (KRW bn) | YoY |
| 1 | Keytruda | Pembrolizumab | MSD Korea | Oncology | 548.1 | +13.3% |
| 2 | Wegovy | Semaglutide | Novo Nordisk Korea | Obesity / GLP-1 | 472.5 | +681.6% |
| 3 | Tagrisso | Osimertinib | AstraZeneca Korea | Oncology | 245.8 | +32.3% |
| 4 | Mounjaro | Tirzepatide | Lilly Korea | Obesity / GIP-GLP-1 | 215.5 | New in 2025 |
| 5 | Dupixent | Dupilumab | Sanofi-Aventis Korea | Immunology | 176.2 | +6.4% |
| 6 | Imfinzi | Durvalumab | AstraZeneca Korea | Oncology | 167.6 | +29.7% |
| 7 | Opdivo | Nivolumab | Ono Pharmaceutical Korea | Oncology | 150.4 | +9.7% |
| 8 | K-CAB | Tegoprazan | HK inno.N | Gastroenterology | 145.2 | +6.3% |
| 9 | Prolia | Denosumab | Amgen Korea | Bone health | 144.5 | -17.3% |
| 10 | Rosuzet | Ezetimibe / Rosuvastatin | Hanmi Pharmaceutical | Dyslipidemia | 128.2 | +4.9% |
Four oncology brands account for KRW 1.112 trillion, or 46.4% of the combined sales of the top 10. Keytruda, Tagrisso, Imfinzi, and Opdivo show that oncology remains the single largest high-value block in the ranking. Yet the metabolic shift is impossible to miss: Wegovy and Mounjaro alone account for 28.7% of the same top-10 total.
The rest of the ranking also shows that Korea’s high-value market is not defined only by new launches. Dupixent remains a major immunology product; K-CAB, a Korean-developed P-CAB, generated KRW 145.2 billion; Rosuzet remained inside the top 10 at KRW 128.2 billion; and Prolia stayed ninth even after a 17.3% decline. This mix matters for competitive intelligence because it combines fast-growth innovation brands with mature products facing lifecycle, pricing, and follow-on competition.
A five-year market that kept expanding
South Korea’s pharmaceutical market expanded from KRW 22.08 trillion in 2021 to KRW 29.05 trillion in 2025, an implied compound annual growth rate of about 7.1% across the period. The annual path was not perfectly linear – growth slowed to 2.9% in 2024 before accelerating to 8.3% in 2025 – but the direction remained positive.
For drug developers and portfolio teams, that growth changes the meaning of a top-10 ranking. A blockbuster in Korea is competing inside a larger market, but the fastest changes are occurring within therapeutic segments: cancer remains a high-value anchor, while obesity has moved from a niche metabolic segment toward the commercial center of the prescription market.
What the K-Orangebook extract adds: regulatory activity remains concentrated in chronic-disease ingredients
The supplied MFDS K-Orangebook extract contains 5,000 records, of which 2,163 fall inside the exact five-year window from 28 October 2021 through 28 October 2026. The extract is not the complete K-Orangebook: the live MFDS K-Orangebook currently shows 23,508 records. Accordingly, the chart below describes the supplied dataset, not total national approval activity.
Approval-record trend in the supplied 5,000-record K-Orangebook extract. 2026 is year-to-date through 26 October. This is an extract-level trend, not a count of all Korean approvals.
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The five plotted calendar years show 809 records in 2022, 683 in 2023, 187 in 2024, 230 in 2025, and 175 in 2026 year-to-date. Because the source is a partial extract, the post-2023 decline should not be treated as evidence that Korean drug approvals collapsed. Its stronger analytical use is to show which ingredients repeatedly appear inside this selected regulatory dataset.
Top active ingredients by approval-record count in the exact five-year window of the supplied extract. Counts measure regulatory-record activity, not sales or prescriptions.
Sitagliptin hydrochloride hydrate leads the five-year extract with 274 records, followed by empagliflozin with 222 and dapagliflozin propanediol hydrate with 183. Metformin and ezetimibe also rank highly. That concentration reinforces a useful commercial-intelligence point: the same Korean market that is rewarding premium innovation in oncology and GLP-1 therapies also shows persistent regulatory activity around diabetes and cardiometabolic medicines, where generic and combination-product competition can be intense.
GLP-1 is no longer a side story – it is reshaping Korea’s drug market
Wegovy and Mounjaro’s rapid rise in South Korea is part of a much broader shift in the GLP-1 market. Patent activity is expanding beyond the current leaders as companies work on new formulations, delivery routes, combination therapies, and next-generation molecules. Our analysis of GLP-1 patents tracks these changes and highlights where future competition is beginning to build.
Wegovy and Mounjaro generated KRW 688.0 billion combined in 2025 distribution sales, exceeding Keytruda as a single-product benchmark.
A separate IQVIA obesity-market analysis reported that South Korea’s obesity-drug market grew from KRW 242.6 billion in 2024 to KRW 819.5 billion in 2025. In that market-specific cut, Wegovy represented 59% of sales and Mounjaro 27%. The product values differ slightly from the broader distribution-sales ranking because the analyses use different market cuts and aggregation, but both point to the same conclusion: GLP-1 therapies drove a step-change in the value of Korea’s obesity-treatment market.
The momentum continued into 2026. HIRA-based data reported by Seoul Economic Daily showed 2.79 million combined Wegovy and Mounjaro prescriptions through August 2026 – about 2.3 times the full-year 2025 total. Mounjaro’s share of the two products’ August prescriptions reached 86.9%. These are prescription records, not unique patients, but they demonstrate how quickly competitive leadership can shift even after a blockbuster launch.
Why this changes competitive and patent intelligence priorities
A revenue ranking becomes strategically useful when it is connected to the events that can change future revenue: new indications, formulation changes, pricing and reimbursement decisions, patent listings, patent expiry, biosimilar or generic entry, litigation, and competitor launches. Korea’s 2025 ranking illustrates several different risk profiles at once. High-value oncology biologics require close monitoring of indications, combination regimens, and follow-on biologics; mature chronic-disease brands face generic and fixed-dose-combination pressure; and GLP-1 products are in a rapid lifecycle race where dose, device, route of administration, supply, and next-generation molecules can alter market position quickly.
The K-Orangebook is especially valuable as one regulatory signal because MFDS describes it as an integrated source covering approved generics, equivalence information, approval dates, and patent-registration indicators. But a blank patent field should never be read as proof that no relevant patent exists, and a patent listing alone does not answer validity, enforceability, expiry, infringement, or freedom-to-operate questions. The most defensible monitoring model links regulatory events with patent-family data and product-level commercial signals.
