Health Corner
Health Corner What’s the difference between getting a weight-loss injection from a doctor vs. self-injecting?
The so-called “weight-loss injections” or “weight-loss pens” currently on the market mainly refer to GLP-1 receptor agonists (such as Saxenda, Ozempic, Wegovy, or Mounjaro, etc.). These medications were originally developed to treat type 2 diabetes, but have gained popularity in recent years due to their significant weight loss effects.
Because weight-loss pens are injectable medications intended for self-administration, many people mistakenly believe they can inject themselves without medical supervision. However, using them without a doctor’s assessment and guidance poses considerable risks. In Hong Kong, these are prescription-only drugs (Class I dangerous drugs). They can only be legally obtained and used with a doctor’s prescription and supervision. Purchasing, possessing, or using them without a valid prescription is illegal. The Department of Health has repeatedly warned the public not to buy such products online or through unregulated channels, as they may be counterfeit, substandard, or improperly stored.
Below is a comparison between “getting a weight-loss injection from a doctor (with medical guidance)” and “self-injecting (after illegal purchase).”
| Category | Doctor-administered (under medical supervision) | Self-injected (illegally purchased online or as parallel import) |
| Legality | Entirely legal. The doctor prescribes and monitors usage. | Illegal! Under the Hong Kong Pharmacy and Poisons Ordinance, purchase/possession/use without a prescription is prohibited, punishable by a fine up to HKD 100,000 and imprisonment up to 2 years. |
| Source of medication | Genuine manufacturer’s products (e.g., Novo Nordisk or Eli Lilly), stored and transported under strict temperature control. | Possible parallel imports, counterfeit, or expired products. Improper storage (no cold chain) may render them ineffective or unsafe. |
| Dosage and treatment plan | Doctor tailors the dosage and escalation plan based on BMI, health condition, and lab results, starting low to minimize side effects. | Self-decided dosage, easily overdosed or underdosed without professional adjustment, increasing risk. |
| Safety and monitoring | Doctor screens for contraindications (e.g., family history of thyroid cancer, pancreatitis, severe kidney disease, pregnancy) and monitors liver/kidney function and blood sugar regularly. | No professional screening, may overlook contraindications; side effects may be ignored or mismanaged (e.g., severe nausea, pancreatitis, hypoglycemia). |
| Side effect management | Doctor teaches proper injection technique and methods to manage GI discomfort (e.g., dosage adjustment, diet modification). Prompt medical help available if problems occur. | Common GI side effects (nausea, vomiting, diarrhea, constipation) often unmanaged. Severe cases may lead to pancreatitis, gallbladder issues, or thyroid tumor risks. |
| Effectiveness and long-term management | Combined with diet and exercise, results are more stable. Doctor monitors progress and prevents rebound weight gain after stopping. | High chance of rebound weight gain (due to appetite return). Without lifestyle guidance, results are short-lived. |
| Cost | Higher (each pen costs several thousand HKD, self-paid), but includes doctor consultations and follow-ups. | Appears cheaper (online prices often half of retail), but risks of counterfeit or degraded drugs make long-term costs higher. |
| Overall risk | Low (under doctor’s supervision). | High (risk of fake drugs, wrong dosage, unmanaged complications, and legal consequences). |
Why professional supervision matters
From the comparison, it’s clear why medical supervision is strongly recommended. You should first consult a general practitioner or endocrinologist for an assessment (including blood tests, BMI measurement, and medical history review). The doctor will determine if you’re suitable for the medication and teach proper subcutaneous injection techniques.
Nowadays, most weight-loss injections are pre-filled pens, making home administration simple—but remember: the medication must still be prescribed by a doctor, and regular follow-ups are essential. When used under proper medical monitoring along with a balanced low-calorie diet and regular exercise, many people can safely achieve 5–20% weight loss, depending on the medication and individual factors, while also improving blood glucose, cholesterol, and cardiovascular health.
Never buy these medications online or from unauthorized sources—they may be counterfeit or parallel imports, and there have been multiple prosecutions in Hong Kong for illegal sales. Also, keep in mind that weight-loss injections are not magic bullets; best results come from pairing them with healthy eating, regular exercise, and long-term lifestyle changes. Otherwise, regaining weight after stopping the medication is very common—even exceeding previous levels.
If you are struggling with excess weight and considering weight-loss injections for health improvement, it’s best to consult a qualified doctor first and decide after a proper evaluation. Weight management is a long-term journey, and safety should always come first.
For any inquiries or to book a professional consultation, please WhatsApp +852 9669 5760 or call 2371 6400.
