Korea Records 2.64 Million Mounjaro Safety Checks as Minor Reviews and Illegal Imports Draw Scrutiny

Rapid growth puts Korea's drug safeguards under scrutiny

South Korea recorded 2,641,523 safety checks involving Mounjaro between its domestic launch in August 2025 and August 2026, including 3,122 checks involving people under 18. Over the same period of market expansion, customs authorities detected a sharp increase in illegal obesity drug imports and found counterfeit products among intercepted shipments from India.

The figures place two separate safety challenges in focus: whether safeguards work during legitimate prescribing and dispensing, and how authorities can control medicines entering through unauthorized channels. They do not establish that 2.64 million people received Mounjaro or that thousands of children were treated with it.

The Health Insurance Review and Assessment Service (HIRA) submitted the latest figures to So Byeong-hoon, a Democratic Party of Korea lawmaker on the National Assembly's Health and Welfare Committee. Mounjaro accounted for almost 65% of the combined 4,062,381 checks recorded for it and Wegovy since their respective Korean launches.

Wegovy registered 1,420,858 checks between October 2024 and August 2026. Mounjaro therefore accumulated about 1.86 times as many checks despite entering the market approximately 10 months later. These are comparisons of safety review activity across different reporting periods, not counts of patients or measurements of market share.

What the DUR figures actually measure

Drug utilization review (DUR) is a safety system used during prescribing and dispensing. It checks medication information for issues such as incompatible drug combinations, age restrictions, duplicate treatment and a patient's medication history. A completed check records that review activity, rather than confirming that a prescription was filled or a dose administered.

The same person can generate multiple checks. The published totals also do not show whether a clinician continued, changed or cancelled a prescription after receiving safety information. That distinction is especially relevant to checks involving minors, because an age related review may precede a decision not to supply the medicine.

Reports differ in how they describe the earlier figures through May 2026. Some call them prescriptions, while another identifies them as DUR checks and explicitly cautions that they are not exact prescription or dispensing totals. Because the underlying figures come from DUR, they should be treated as checks unless separate dispensing records establish otherwise.

Mounjaro and Wegovy are not covered by Korea's national health insurance for obesity treatment, making comprehensive prescription and dispensing totals harder to compile. DUR records provide a useful indicator of activity, but they cannot independently establish treatment eligibility, actual medicine use or the frequency of inappropriate prescribing.

Monthly checks rose almost 22 times

Mounjaro's monthly checks increased from 18,579 at launch to 404,602 in August 2026, approximately 21.8 times the initial figure. The August 2026 total was also about 20.7% above June's 335,306 checks. The reported milestones show growth across successive periods rather than a single isolated surge.

• October 2024: Wegovy launched in Korea.
• August 2025: Mounjaro launched, recording 18,579 checks that month.
• December 2025: Monthly Mounjaro checks reached 128,979.
• March 2026: Monthly checks reached 228,199.
• May 2026: Monthly checks reached 273,140, with cumulative checks at 1,501,161.
• June 2026: Monthly checks reached 335,306.
• August 2026: Monthly checks reached 404,602, bringing the cumulative total to 2,641,523.

The earlier cumulative figures were released through Han Zee-a, a People Power Party lawmaker on the parliamentary health committee. Between the May and August endpoints, Mounjaro's cumulative total increased by 1,140,362 checks, or about 76%. Wegovy's total increased from 1,228,867 to 1,420,858 over those same endpoints, a rise of about 15.6%.

Clinics dominate, while younger adults account for most checks

Neighborhood clinics accounted for 2,399,390 Mounjaro checks, or 90.8% of the total through August 2026. They also accounted for 1,166,925 Wegovy checks, or 82.1%. The concentration means that any review of how DUR warnings operate in practice will depend heavily on what happens in routine clinic care.

The earlier age breakdown through May showed 794,781 Mounjaro checks involving people in their 20s and 30s, representing 52.9% of its 1,501,161 checks. People in their 30s accounted for 36%, followed by those in their 40s at 27.1%, their 20s at 16.9% and their 50s at 14.6%.

For Wegovy, people in their 20s and 30s accounted for 46.4% of checks through May. Mounjaro's share for those ages was therefore 6.5 percentage points higher. These figures describe the age distribution of checks, not the number of distinct patients.

Younger adult demand has prompted concern about cosmetic use, but age alone does not establish misuse. The DUR figures do not disclose body mass index, diagnoses or the medical reason for each review, so they cannot show how many people sought treatment outside the approved criteria.

Minor totals require caution and clarification

Of the 3,122 Mounjaro checks involving people under 18 through August 2026, 39 involved children under 10 and 3,083 involved those aged 10 to under 18. The combined minor total represented approximately 0.12% of all Mounjaro checks.

Tirzepatide, Mounjaro's active ingredient, is approved in Korea for adults. By contrast, Wegovy and some Saxenda products have authorization for adolescents aged 12 to under 18 who meet specified conditions. Approval for one obesity medicine cannot be assumed to apply to another.

There is also an unresolved difference between the reported age series. Earlier accounts described monthly teenage checks rising from 82 in August 2025 to more than 1,000 in December, 1,739 in January 2026 and 2,594 in May. The January and May figures alone sum to 4,333, exceeding the later cumulative total of 3,122 for people under 18.

The labels are not identical: teenagers can include ages 18 and 19, while the later tally excludes everyone aged 18 or older. The published figures do not provide enough detail to determine whether that age distinction fully explains the difference or whether another reporting definition is involved. The two series should not be treated as directly comparable.

Neither series establishes how many minors actually received Mounjaro. Determining whether warnings prevented treatment, or whether prescriptions proceeded outside the adult authorization, would require records of the decisions made after each check.

Approved treatment criteria differ from cosmetic demand

Mounjaro acts on receptors for two hormones, GLP-1 and glucose dependent insulinotropic polypeptide (GIP), which are involved in appetite and blood sugar regulation. It is used to treat obesity and type 2 diabetes, but its Korean authorization for chronic weight management sets specific eligibility criteria.

Adults qualify under that indication with an initial body mass index (BMI) of at least 30, or a BMI of 27 to below 30 together with at least one condition related to weight. Those conditions include hypertension, abnormal blood lipid levels, type 2 diabetes, obstructive sleep apnea and cardiovascular disease. BMI relates weight to height and is used as a screening measure.

The medicine must be used alongside a diet with fewer calories and exercise. Prescribing for weight management outside those criteria falls outside that approved indication, although the DUR totals cannot identify how often that happened.

A 2025 Korea Disease Control and Prevention Agency survey illustrates the broader demand for weight control: 68.5% of adults said they were trying to lose or maintain weight. Among women aged 19 to 29 who were underweight, with a BMI below 18.5, 16.2% were dieting. More than half of women at a normal weight were also trying to lose weight. Those findings provide context for concern about unnecessary treatment, but do not establish who used Mounjaro.

Price gaps help explain purchases in Japan

A month's supply of Mounjaro at the lowest 2.5 milligram dose was reported to cost about 10,000 yen in Japan, compared with 280,000 to 350,000 won in Korea. Reports translate the Japanese price as approximately 84,000 or 85,000 won. Using 85,000 won, it amounts to roughly 24% to 30% of the Korean price.

Japan reduced Mounjaro's price by 25% in August 2026. Eli Lilly Korea said the products sold in Japan and Korea are identical. Accounts of Korean travelers obtaining prescriptions from Japanese medical institutions describe a search for cheaper treatment, with hospital recommendations circulating on social media.

The lowest dose comparison should not be confused with the reported cost of treatment at the highest dose, which typically exceeds 700,000 won a month in Korea. An unnamed woman in her early 30s described deciding against Mounjaro because she could not afford to spend more than 500,000 won monthly on weight treatment.

For obesity treatment in Korea, patients bear the full cost because Mounjaro is not covered by national health insurance, and medical institutions can set prices for services outside that coverage. The price difference creates an incentive to buy abroad, but an overseas prescription does not by itself authorize importation into Korea.

Illegal imports rose through mail and passenger luggage

Korea Customs Service data show 5,030 illegal obesity drug import cases from January through August 2026, compared with 1,189 during all of 2025 and four in 2024. The eight month total was approximately 4.2 times the previous full year total. These are detected cases, not counts of doses, buyers or all attempted imports.

International mail accounted for 3,913 cases in 2026, approximately 77.8% of the total. Travelers' baggage accounted for 1,097 and express cargo for 20. Across the three reported years, the combined 6,223 cases consisted of 4,961 mail cases, 1,232 baggage cases and 30 express cargo cases.

The countries of origin differed by route. Among travelers' items seized in 2026, 63.3% came from Japan and 21.8% from China. Through May, 95.6% of intercepted international mail shipments came from India. Baggage seizures rose from 134 in all of 2025 to 656 in the first half of 2026.

The Ministry of Food and Drug Safety (MFDS) designated Mounjaro, Wegovy and similar products as hazardous drugs for import control in October 2024. Without the required authorization or exemption documentation, they cannot be brought into Korea even for personal use or in small quantities. Intercepted shipments are destroyed.

Customs authorities found counterfeit products among Mounjaro shipments from India. Analysis by the Korea Customs Service and researchers at Chung-Ang University's College of Pharmacy found varying active ingredient levels and unidentified impurities in seized Indian products. Those findings should be distinguished from medicines prescribed by Japanese institutions; the same quality defects have not been established for those products.

Online enforcement targets sales and intermediaries

The MFDS also identified 949 illegal online postings during nine months of 2026 and requested that the Korea Communications Standards Commission and other bodies block access. The cases included direct sales, referrals and advertising for GLP-1 obesity medicines.

• 716 postings sold medicines or directed users to sales sites.
• 129 cafe or blog postings referred users to sales sites.
• 72 social media postings supplied private chat contact details.
• 32 postings involved transactions between individuals.

The Pharmaceutical Affairs Act prohibits online medicine sales as well as brokering and advertising those sales. These medicines require a prescription and appropriate guidance on dose and timing. Removing a referral or chat contact is therefore part of enforcement, even when the posting does not display a completed transaction.

The ministry warned that products bought directly from overseas may be counterfeit or defective, with manufacturing and distribution histories that cannot be confirmed. Temperature control during transport is another concern. Storage requirements depend on the product, so an informal delivery route cannot be assumed to preserve medicine quality.

The ministry also warned that buyers may have difficulty obtaining a recall or compensation if harm occurs. The 949 postings are a separate enforcement measure from the 5,030 customs cases; adding them would not produce a valid total of illegal purchases.

Lawmakers seek safeguards that preserve treatment access

The Ministry of Health and Welfare and MFDS were considering designating GLP-1 obesity treatments as medicines at risk of misuse. The proposed designation could require warnings on containers and packaging and internal management records at medical institutions and pharmacies. The reports do not establish that the proposal has been finalized or give an implementation date.

Han Zee-a, the People Power Party lawmaker who released the earlier DUR figures, called for stronger prescription management while protecting legitimate access:

"Patients who require treatment should continue to have access, but management of GLP-1 obesity drugs should shift from distribution controls toward prescription management using the DUR system to prevent misuse among adolescents and for cosmetic purposes," Han said.

So Byeong-hoon, the Democratic Party lawmaker who obtained the later figures, called for a review of whether safeguards work in clinical settings and for coordination across prescribing, distribution and border enforcement:

As oversight spans multiple agencies, covering not only prescriptions at medical institutions but also drug distribution and illegal imports, relevant authorities should share information to reduce gaps in safety management.

The unresolved issues are concrete: how many checks led to actual dispensing, what happened after age warnings, why the teenage and under 18 series differ, and whether patients met approved treatment criteria. No hearing, vote or deadline is specified. Answering those questions would distinguish rapid growth in safety review activity from evidence that safeguards succeeded or failed.

Key Points

• Mounjaro recorded 2,641,523 DUR checks from August 2025 through August 2026, not 2.64 million confirmed patients.
• Checks involving people under 18 totaled 3,122; they do not prove treatment or illegal prescribing.
• Earlier teenage figures use a different age label and cannot be directly reconciled with the later minor total.
• Clinics accounted for 90.8% of Mounjaro checks.
• Customs detected 5,030 illegal obesity drug import cases through August 2026, mostly through international mail.
• Regulators identified 949 illegal online postings and requested access blocking.
• Lawmakers called for stronger prescription oversight and agency information sharing while preserving access for patients who need treatment.