Hanmi's Half-Price Obesity Shot Takes On Mounjaro. Wegovy Feels It First

On October 7, Korea approved its first homegrown obesity injection. Its first month costs roughly half of a starter month of Mounjaro.

The obvious target is Eli Lilly, which holds 86.7% of the market. Yet six days later, the company that rushed to Korea's national health insurer was Novo Nordisk, on behalf of Wegovy.

The shot is Eppe, from Hanmi Pharmaceutical. The first month costs 129,800 won, about $97. Hanmi has not published its supply price; a spokesperson said only that the number was set with "patient access as the top priority."

A half-price shot will not dent Mounjaro's 90%. What it bites into is Wegovy's 13%.

01 | Korea's obesity market has one dominant player

Less than a year after launch, Mounjaro held 86.7% of Korea's GLP-1 weight-loss market in June. Wegovy had 13.2%.

The challenger took a long road. Eppe's generic name is efpeglenatide. In 2015 Hanmi licensed it to Sanofi as a diabetes drug for a €200 million upfront fee. In May 2020, Sanofi shut down diabetes research and handed back all rights, saying the decision had nothing to do with efficacy or safety. Hanmi's shares fell 7.17% that morning.

Hanmi did not look for another global partner. In July 2023 it turned the molecule into an obesity drug and ran Phase 3 only in Korea, pitching it as a "Korean-customized GLP-1." The global blockbusters were tested mostly in severely obese Western patients; Koreans are much lighter on average. Hanmi was betting on a slot that was good enough, gentler and cheaper.

The Korean Phase 3 enrolled 448 adults with obesity and no diabetes. At Week 40, patients on Eppe had lost 9.75% of body weight on average, versus 0.95% on placebo, and almost half lost at least 10%. Women with a BMI under 30 lost 12.20%, exactly the patients Hanmi wants.

This month Eppe became Korea's 45th homegrown new drug. Hanmi has set an annual sales target of more than 100 billion won, about $74 million.

The ticket is valid only in Korea. What it is worth depends on whose patients it can take.

02 | Same weekly shot, different switches

Think of the GLP-1 receptor as a doorbell on the surface of a cell. Ring it, and the pancreas releases more insulin while the brain gets the signal that it has eaten enough.

All three injections ring that bell. They ring it differently.

Mounjaro rings two bells at once. Its active ingredient, tirzepatide, hits both the GLP-1 and the GIP receptors, and the two signals push weight down together.

Wegovy rings one. Semaglutide works through GLP-1 alone. It was the previous champion.

Eppe also rings one, but it carries a large backpack. Hanmi's LAPSCOVERY platform links an exendin-4-like peptide, through a PEG linker, to an Fc fragment, the tail end of an antibody. The molecule gets big enough that the kidneys filter it out slowly, which is what makes once-a-week dosing possible.

Fig. 1 | Mounjaro hits GLP-1 and GIP; Wegovy and Eppe hit GLP-1 only, and Eppe uses an Fc fragment to stay in circulation longer.

The number of switches shows up on the scale. In their main trials Mounjaro produced up to 20.9% weight loss at 72 weeks, Wegovy 14.9% at 68 weeks, and Eppe 9.75% at 40 weeks. The trials differ in length and population, so the comparison is about orders of magnitude.

What Eppe offers in exchange is a gentler stomach: nausea in 16.6% of patients and vomiting in 11.6%, below the rates reported for Wegovy.

On efficacy, Eppe lives on the same floor as Wegovy. Mounjaro is upstairs.

03 | Lilly, Novo and Hanmi: what each one competes with

Lilly competes on efficacy, and won. Mounjaro launched in Korea in August 2025. A four-week supply of the 2.5 mg starter dose costs about 270,000 won, the most expensive of the three.

It still sells the most. Records from Korea's Health Insurance Review and Assessment Service (HIRA) show 335,306 Mounjaro prescriptions in June. The starter dose alone accounted for 142,434, or 19.6 times Wegovy's starter-dose count. Nineteen of every twenty new patients chose Mounjaro.

The speed of the takeover is striking. Mounjaro wrote 18,579 prescriptions in its first month. By June 2026 that number was roughly eighteen times higher, and it had passed Wegovy within four months.

Wegovy went the other way. Its monthly prescriptions peaked at 88,895 in May 2025 and slipped to 65,410 by June 2026, even after Novo brought in local partner Chong Kun Dang to co-market it.

Novo competes on insurance, because it already tried price. Wegovy launched in Korea in October 2024 at about 370,000 won for four weeks. Before Mounjaro arrived, Novo cut the lowest dose by 42%, to roughly 200,000 won.

It lost anyway. On October 13, Korean media reported that Novo had applied to HIRA for national insurance coverage of Wegovy. The drug has to clear a cost-effectiveness review and an assessment of its budget impact.

Hanmi competes on price, and front-loads the discount. According to the industry price list, Eppe's starter dose is 37% cheaper than Wegovy's and 53% cheaper than Mounjaro's. It is also made in Hanmi's own Korean plant, out of reach of import shortages.

Fig. 2 | Eppe is the cheapest way in; Mounjaro is the most expensive and still holds 90% of the market.

In Korea, the most expensive drug won. Price has already failed once against Mounjaro, and Novo learned that firsthand.

04 | Half price lasts one month

Eppe's price climbs with the dose. According to quotes obtained by the Seoul Economic Daily on October 14, each step up costs more:

1. Month 1 (2 mg and 4 mg): 129,800 won
2. Month 2 (6 mg): 228,800 won
3. Month 3 (8 mg): 277,200 won
4. Month 4 (10 mg): 299,200 won, about $223

Those are supply-side figures. Aju Press, citing industry estimates, put a patient's actual first-month bill at 140,000 to 200,000 won once clinic and pharmacy charges are added.

Month four costs 2.3 times month one. At the maintenance dose, Eppe is only 17% cheaper than Wegovy and 19% cheaper than Mounjaro.

Fig. 3 | The discount is concentrated in the first month; at maintenance it shrinks below 20%.

For a Mounjaro patient, switching to Eppe saves about a fifth each month and gives up roughly half the weight loss. That is a bad trade.

For a Wegovy patient, the math is different: the same efficacy tier, a lower price at every step, and a domestic supply chain.

Hanmi does not have to beat Mounjaro. At 299,200 won a month, 100 billion won of annual sales works out to about 28,000 patients treated for a full year. Mounjaro wrote 335,000 prescriptions in June alone. What Hanmi needs is less than a tenth of that single month, and the easiest place to find it is Wegovy's 13.2%.

That is why Novo is hurrying to the insurer. Industry officials told the Korea Herald that if Wegovy clears review its price advantage would be significant, and that Mounjaro and Eppe would almost certainly apply as well.

Pressure is also coming from abroad. Mounjaro 2.5 mg costs about 270,000 won for four weeks in Korea and about 10,000 yen in Japan, roughly a third as much. Korea Customs caught 5,030 cases of smuggled obesity drugs in the first eight months of 2026, 4.2 times a year earlier, and Koreans have nicknamed the Japanese-bought version "sushijaro." In China, Mounjaro's price has fallen by as much as 66%.

Chung Sang-won, director of pharmacy innovation at the Korea Pharmaceutical Association, put it plainly: "Obesity drugs often require long-term use, so cost can play a significant role." Long-term use is exactly where an insurer's money matters more than a launch discount.

Korea's weight-loss drugs are being pushed from cosmetic, out-of-pocket spending toward reimbursed treatment for a chronic disease. Whichever drug the state first accepts as a medicine gets the next decade's price.

Fig. 4 | A schematic of the company strategies described above, based on the reporting cited in this article. It is not prescribing guidance.

05 | Taiwan pays NT$9,500 and up, and is watching Korea

Taiwan stands at the same crossroads. The Reporter found in January that Mounjaro sells for NT$9,500 to NT$15,000 in Taiwan, fully out of pocket for weight loss, while national insurance conditionally covers only three diabetes-only GLP-1 drugs.

Korea and Taiwan run similar single-payer systems and face the same question: whether weight loss is a lifestyle purchase or the treatment of a disease. How HIRA handles Wegovy is the closest test case Taiwan's insurer has.

Half price lasts a month. What will actually redraw Korea's market-share table is when HIRA puts Wegovy on the reimbursement list. Until then, the drug losing patients to Eppe is Wegovy itself.

This article is industry and company analysis, not investment or medical advice.

References

1. Wegovy seeks insurance edge in Korea's obesity drug war｜The Korea Herald｜2026-10-13｜https://www.koreaherald.com/article/10901056
2. Hanmi's Efpe Obesity Drug to Cost 129,800 Won in First Month｜Seoul Economic Daily｜2026-10-14｜https://en.sedaily.com/finance/2026/10/14/hanmis-efpe-obesity-drug-to-cost-129800-won-in-first-month
3. Price War Heats Up as Novo Seeks Insurance Coverage for Wegovy in Korea｜Seoul Economic Daily｜2026-10-16｜https://en.sedaily.com/finance/2026/10/16/price-war-heats-up-as-novo-seeks-insurance-coverage-for
4. Korea's 1st homegrown obesity drug likely to intensify price competition｜The Korea Times｜2026-10-16｜https://www.koreatimes.co.kr/business/companies/20261016/koreas-1st-homegrown-obesity-drug-likely-to-intensify-price-competition
5. Hanmi's Eppe priced at 129,800 won for first month (Hanmi spokesperson on pricing, in Korean)｜News Journalism｜2026-10-15｜https://www.ngetnews.com/news/articleView.html?idxno=554556
6. Korea's first GLP-1 obesity drug wins approval with less weight loss but fewer side effects｜Korea JoongAng Daily｜2026-10-08｜https://www.koreajoongangdaily.com/business/koreas-first-glp1-obesity-drug-wins-approval-with-less-weight-loss-but-fewer-side-effects/12910491
7. Korea's Homegrown GLP-1 obesity therapy with Favorable Efficacy and Safety Nears Filing (Phase 3 Week 40 interim)｜Hanmi Pharmaceutical｜2025-10-27｜https://www.hanmipharm.com/about/investor-relations/press/detail-3763.hm
8. Wegovy Falls 20-Fold Behind Mounjaro in New Prescriptions, May Cut Prices Again｜Seoul Economic Daily｜2026-07-30｜https://en.sedaily.com/culture/2026/07/30/wegovy-falls-20-fold-behind-mounjaro-in-new-prescriptions
9. Sanofi to return efpeglenatide rights to Hanmi｜Korea Biomedical Review｜2020-05-14｜https://www.koreabiomed.com/news/articleView.html?idxno=8244
10. Hanmi files phase 3 IND for Korean-customized obesity drug efpeglenatide｜KED Global｜2023-07-31｜https://www.kedglobal.com/newsView/ked202307310013
11. LAPSCOVERY: Long-Acting Protein/Peptide Discovery platform technology｜LAPAL｜2026-10-17｜https://lapal.ch/technology/lapscovery-long-acting-protein-peptide-discovery-platform-technology
12. Social media sales, pharmacy back doors and Japan shoppers: Taiwan's illicit GLP-1 network (in Chinese)｜The Reporter｜2026-01-19｜https://www.twreporter.org/a/illicit-drug-distribution-of-glp-1-gip-in-taiwan-1
13. Hanmi's new obesity drug to launch this month at half Mounjaro's price｜Aju Press｜2026-10-15｜https://www.ajupress.com/view/20261015085413145
14. USD exchange rates (TWD 32.36, KRW 1,342.74, JPY 158.09)｜ExchangeRate-API｜2026-10-16｜https://open.er-api.com/v6/latest/USD