One Ho Chi Minh City resident, identified as D.L.H.T., praised the weight-loss effects of the Mounjaro 2.5mg (tirzepatide) injection pen on social media, claiming she lost 3.5 kilograms after a single dose and experienced a significant reduction in appetite. Similar testimonials have helped fuel demand for the product, which is widely sold online as an imported “hand-carried” item.
Posing as a prospective customer, Sai Gon Giai Phong (SGGP) reporters contacted an online vendor selling Japanese weight-loss injection pens. The seller claimed the product could help users lose between three and five kilograms and described the 2.5mg dose as completely safe. A package containing two pens was offered for around VND1.5 million (US$57), with instructions for weekly injections.
However, the results have not been uniformly positive. While some users reported losing weight, others experienced severe side effects, raising concerns about the safety of these products when purchased through unofficial channels.
A 43-year-old woman in Ho Chi Minh City said that she suffered prolonged exhaustion after following dosage instructions provided by a seller. She described feeling constantly fatigued, losing all desire to eat and experiencing nausea, dizziness and episodes of low blood pressure. On one occasion, her condition became so severe while she was outside that she had to call family members for assistance.
Another woman reported persistent fatigue, rapid heartbeat and ringing in the ears after using four injection pens. Social media users have also shared accounts of relatives requiring hospitalization after overusing weight-loss injections.
SGGP's investigation found that many buyers are unaware of the origin and composition of the products they purchase. Far from being dietary supplements or cosmetic products, the injections are prescription medicines for obesity and type 2 diabetes, including GLP-1-based drugs such as liraglutide, semaglutide and tirzepatide.
Doctor Le Thuan Linh, M.Sc., Specialist Level I, Head of the Nutrition Department at Thu Duc General Hospital, noted that the U.S. Food and Drug Administration (FDA) has approved only three injectable medications for obesity treatment, including liraglutide 3mg, semaglutide 2.4mg and tirzepatide.
In Vietnam, the Ministry of Health has approved liraglutide 3mg, marketed as Saxenda, for obesity treatment under strict conditions. The medication is intended for adults with a body mass index (BMI) of 27 or higher who also have weight-related health conditions, or for individuals with a BMI of 30 or above. It is contraindicated for people with certain medical histories, including medullary thyroid cancer and multiple endocrine neoplasia syndrome type 2.
Medical experts emphasize that these medications must be prescribed and monitored by qualified healthcare professionals. Documented risks include acute pancreatitis, gallbladder disease, acute kidney injury, severe hypoglycemia, depression and, in rare cases, suicidal thoughts.
Doctor Van Viet Thang, Specialist Level I Physician of Intensive Care and Poison Control Department, Vung Tau General Hospital, said that these injection pens promote weight loss by suppressing appetite and prolonging feelings of fullness. The greatest concern, however, is that many people misuse the drugs in pursuit of rapid weight loss, taking them without medical supervision or proper guidance. Such misuse can lead to persistent fatigue and significantly affect daily activities and overall quality of life.
There is no such thing as a miracle weight-loss drug, Doctor Van Viet Thang said. “Effective and sustainable weight loss requires a calorie-controlled diet and increased physical activity. For patients undergoing obesity treatment, strict adherence to prescribed treatment plans is essential.
He also warned that these medications require strict refrigerated storage. Products sold through unofficial channels may be improperly stored or of unknown origin, potentially compromising their safety and effectiveness.
Common side effects include nausea, diarrhea, constipation, bloating, abdominal pain, heartburn, acid reflux, early satiety and loss of appetite. Health experts strongly advise consumers not to self-medicate and to seek professional medical guidance before using any prescription weight-loss treatment.
