The obesity drug Maunjaro has been prescribed to pregnant women, the elderly and even children under 13 — groups for whom its use is restricted or contraindicated — just one year after its domestic launch, newly released data shows.
Health authorities confirmed that Maunjaro was prescribed more than 300 times to pregnant women, despite explicit warnings against its use during pregnancy. The drug was also prescribed more than 100 times to children under 13, a population in which its safety and efficacy have not been established. Among the elderly, tens of thousands of prescriptions were issued, raising concerns about a growing safety blind spot amid the Maunjaro craze.
According to data submitted to the National Assembly's Health and Welfare Committee by the Health Insurance Review and Assessment Service, Maunjaro was prescribed 325 times to pregnant women in the roughly one year between its domestic launch in August 2025 and July this year.
The prescribing information for Maunjaro prefilled pen injections (2.5 mg/0.5 mL), as listed in the Ministry of Food and Drug Safety's integrated drug information system, states that the drug must be discontinued in pregnant women. The ministry's guidelines strictly limit its use in pregnant women, breastfeeding women, women of childbearing age, children and the elderly. Data on the drug's use in pregnant women is described as very limited, and its active ingredient, tirzepatide, has shown reproductive toxicity in animal studies. The drug must not be used during pregnancy and must be discontinued if a patient becomes pregnant or wishes to become pregnant during treatment. Women of childbearing age are advised to use contraception when starting treatment.
For breastfeeding women, it is not known whether tirzepatide or its metabolites are excreted in breast milk. Because the risk to newborns and infants cannot be ruled out, the drug must not be used while breastfeeding.
More than 100 prescriptions were also issued to children under 13 during the same one-year period from August 2025 through July this year. Despite Maunjaro's unestablished safety and efficacy profile in pediatric patients, the drug is being prescribed to young children, prompting calls for scrutiny of the purpose and circumstances behind such prescriptions and whether off-label use is being properly monitored.
Among the elderly, Maunjaro prescriptions have spread even faster. Prescriptions for patients aged 65 and older exceeded 36,000 during the same period, with monthly figures continuing to rise. The Ministry of Food and Drug Safety's approval documentation notes that clinical trial data "cannot rule out greater sensitivity in some elderly patients," and treatment experience in patients aged 85 and older is described as very limited.
While no overall differences in safety or efficacy were observed between elderly and younger patients, pooled data from clinical trials assessing the drug's effectiveness in treating diabetes found that greater sensitivity in some elderly patients cannot be excluded. Experience with patients aged 85 and older remains very limited.
Ultimately, as the obesity drug market has grown explosively in the year since Maunjaro's launch, questions are mounting over whether the safeguards built into the prescribing process are adequately screening out high-risk groups such as pregnant women and children. Separately, data submitted by the Ministry of Food and Drug Safety to the office of People Power Party lawmaker Baek Jong-heon showed that 1,261 adverse events were reported in the 11 months from August 2025, when Maunjaro was launched domestically, through June this year. Of those, 916 cases — 72.6 percent of the total — were reported this year alone.
"If a drug that the Ministry of Food and Drug Safety has explicitly designated for discontinuation was prescribed to pregnant women more than 300 times, this is not something that can be taken lightly," Baek said. "Amid the obesity treatment craze, one cannot help but suspect that the most basic prescribing principles for patient protection are breaking down." He called on the Ministry of Health and Welfare and the Ministry of Food and Drug Safety to conduct a full investigation into prescribing practices for high-risk groups including pregnant women and children, rather than leaving the matter solely to the judgment of doctors and patients, and to swiftly develop countermeasures.
kty@heraldcorp.com
