Medically reviewed by Dr Sin Yong · Last reviewed · 19 min read · Doctor-performed, never delegated · Jump to questions
Dr Sin Yong · MBBS (NUS) · MRCS (Edin) · MSc Aesthetic Medicine with Distinction (Queen Mary, London) · MSc Practical Dermatology (Cardiff) · International KOL
GLP-1 medications — Wegovy (semaglutide), Mounjaro (tirzepatide), Saxenda (liraglutide) — have changed what medicine can offer for weight. They are also prescription-only medicines in Singapore: you qualify for them through a medical assessment, you are titrated and monitored through them, and you are told honestly what they do not fix. This page explains the class; suitability is a consultation decision.
Weight loss medication in Singapore means prescription-only GLP-1 medicines such as Wegovy (semaglutide), Mounjaro (tirzepatide) and Saxenda (liraglutide), regulated by HSA. Eligibility is decided by medical assessment, followed by supervised titration and monitoring, and the medicines are prescribed by a doctor, not sold.
Appetite, satiety and weight defence are hormonally regulated — which is why diets fail so predictably and why the arrival of GLP-1 receptor agonists matters. These medications work with the body’s own appetite signalling rather than against it. That is genuinely new. What has not changed: they are serious prescription medicines, with real side effects, real eligibility criteria and real consequences when used casually or bought from unregulated sources.
In Singapore these are prescription-only medicines regulated by HSA — they cannot be sold to you on request, and any channel offering them without assessment should worry you. Here the sequence is medical: history, examination and metabolic screening first; an eligibility decision against established criteria; then a supervised programme — dose titration, side-effect management, nutrition and muscle preservation, and a maintenance plan for the day the medication stops.
GLP-1 (glucagon-like peptide-1) is a gut hormone released after eating. It signals satiety to the brain, slows gastric emptying and supports insulin regulation. GLP-1 receptor agonist medications amplify this signalling: appetite tends to quieten, and many patients describe less of the constant food-noise they had before, although response varies between individuals. Semaglutide (Wegovy — weekly injection) and liraglutide (Saxenda — daily injection) work on this receptor; tirzepatide (Mounjaro — weekly) adds a second incretin pathway, GIP, alongside GLP-1.
The honest physiology cuts both ways. Weight lost this way includes muscle unless protein intake and resistance work are planned — one reason supervision matters. Rapid facial volume loss is real enough to have a nickname (“Ozempic face”), and appetite returns when the medication stops, which is why an exit and maintenance plan belongs in the programme from day one — not improvised at the end. These are management decisions, and they are the difference between a prescription and a programme.
These medicines are indicated for defined BMI thresholds, adjusted for comorbidities — an eligibility decision made at medical assessment, not a lifestyle purchase. If you do not qualify, you will be told, and told why.
Wegovy — semaglutide, weekly. Saxenda — liraglutide, daily. Mounjaro — tirzepatide, weekly, acting on GLP-1 and GIP receptors. Which suits you, if any, depends on your history, goals and response — not on which name you searched.
Nausea, reflux and constipation are common early and usually managed with titration. Gallbladder issues and pancreatitis are recognised, less common risks. This is exactly why supervision and a real medical history matter.
A meaningful share of unsupervised GLP-1 weight loss is muscle. Protein targets, resistance training and body-composition tracking are built into the programme so that muscle is protected as far as possible.
Rapid loss deflates structural facial fat — the “Ozempic face” pattern. Planning for it belongs in the programme; restoring it afterwards is its own discipline — see Ozempic face treatment, volume restoration and collagen biostimulators.
Medication changes mass, not architecture. Residual pockets and laxity are addressed separately — fat freezing, body contouring — once weight is stable.
“A prescription medicine is not a shortcut you buy. It is a treatment you qualify for and are supervised through.”Dr Sin Yong
Reference: Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021;384(11):989-1002.
History, examination, metabolic screening and body composition. Eligibility for prescription therapy is decided against established criteria — and alternatives are discussed if medication is not appropriate.
If indicated, therapy starts low and is titrated stepwise, which is how early side effects are kept manageable. You know what to expect before the first dose.
Regular reviews track weight, body composition, side effects and nutrition. Protein and resistance-training targets protect muscle while the scale moves.
Appetite physiology returns when medication stops — so the maintenance strategy, and any facial or body contour planning, is built before that day, not after it.
In a sense, yes: GLP-1 medications reduce appetite, but they do it by amplifying a satiety hormone the gut already releases after eating, rather than by stimulating the nervous system in the way older appetite suppressants do.
That distinction matters when people search for an appetite suppressant in Singapore. Older centrally acting prescription appetite suppressants, such as phentermine, are a different class with their own risks and limits on duration of use. GLP-1 receptor agonists (semaglutide, liraglutide) and the dual GIP and GLP-1 agonist tirzepatide also slow gastric emptying and support insulin regulation, which is part of why they are studied as treatments for weight-related disease rather than as appetite pills. This page is about the GLP-1 class.
All of these are prescription-only, and none belongs in a purchase decision made online. Slimming products marketed as natural appetite suppressants are a separate concern: HSA has repeatedly warned about products found to contain undeclared medicines.
Whether any medication is appropriate, and which, is decided at a medical assessment.
They should be avoided. In September 2026, HSA warned the public about prescription medicines and unapproved injectable peptides being obtained through unauthorised channels, including social media.
The warning covers two groups. The first is approved GLP-1 medicines such as semaglutide, liraglutide and tirzepatide, which HSA notes are prescription-only and can cause serious harm when used without medical supervision. The second is injectable peptides still in clinical development, such as retatrutide and cagrilintide, which are not approved for use.
The practical problem is that a buyer cannot know where or how such a product was made, whether it contains the stated ingredient, or whether the dose is correct. Injecting it adds the risks of contamination and dosing errors on top of the medicine's own side effects.
A doctor-supervised route exists for a reason: eligibility is checked, the dose is titrated, side effects are managed and there is a plan for stopping. If a seller offers any of these products without a prescription, that is the warning sign.
GLP-1 medication is not suitable for everyone, and part of the medical assessment is identifying the people for whom it is the wrong choice or needs extra care.
It is not used in pregnancy or while breastfeeding, and people planning a pregnancy are advised to stop it beforehand. A personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2, previous pancreatitis, gallbladder disease and significant gastro-intestinal conditions such as gastroparesis all need careful consideration. A current or past eating disorder is an important part of the history, because appetite-reducing medication can be harmful in that setting.
Other medicines matter too. Taken with insulin or certain diabetes tablets, these medicines can increase the risk of low blood sugar. Tirzepatide can make oral contraceptives less reliable around the start of treatment and after dose increases. Anyone having a procedure under sedation or general anaesthetic should tell the team they are taking a GLP-1 medicine, because slowed stomach emptying is relevant to anaesthetic safety.
If medication is not appropriate, that is said plainly, along with what the alternatives are.
| Option | What it does | What it cannot do | Typical recovery | Who it tends to suit |
|---|---|---|---|---|
| Structured lifestyle programme (nutrition, protein, strength training, sleep) | Builds the habits that underpin any weight plan and protect muscle | Override the body's hormonal defence of weight on its own for many people | Not a procedure | Everyone, whether or not medication is prescribed |
| GLP-1 receptor agonist (semaglutide weekly, liraglutide daily); prescription-only | Amplifies the body's satiety signalling and slows gastric emptying, with dose titration and monitoring | Preserve muscle by itself, reshape the body, or keep appetite changed after it is stopped | Not a procedure; nausea, reflux and constipation are common early and managed with titration | Adults who meet eligibility criteria at medical assessment |
| Dual GIP and GLP-1 receptor agonist (tirzepatide weekly); prescription-only | Acts on two incretin pathways, GIP and GLP-1, rather than one | Remove the need for supervision, muscle preservation or a maintenance plan | Not a procedure; gastro-intestinal effects similar to the GLP-1 class, managed with titration | Adults who meet eligibility criteria, where the prescribing assessment favours it |
| Fat freezing and body contouring | Addresses discrete pockets of fat and contour once weight is stable | Produce weight loss or treat obesity | Varies with the treatment; discussed beforehand | People at a stable weight with a localised area that remains |
| Metabolic and bariatric surgery, referred to a bariatric surgical team | Changes the anatomy of the stomach or gut to alter appetite and absorption | Remove the need for lifelong nutritional follow-up and lifestyle change | Surgical recovery guided by the operating team | People with a higher BMI or significant weight-related conditions for whom surgery is advised after specialist assessment |
Medically reviewed by Dr Sin Yong · Updated 7 October 2026
People who want a quick cosmetic change below the eligibility criteria, or who will not attend reviews, tend to respond poorly, and for them medication is the wrong tool.
Nausea, reflux and constipation are common early and usually settle with gradual dose titration. Reduced appetite is the intended effect, but it can lead to low protein intake and loss of muscle if training and nutrition are not planned. Rapid weight loss can deflate facial fat, the pattern nicknamed Ozempic face. Gallbladder problems and pancreatitis are recognised, less common complications. Medicines obtained without assessment or from unregulated sources add risks of wrong dose, contamination and unrecognised interactions. This is why history, screening and follow-up are built around any prescription.
The fee depends on which medicine, if any, is prescribed, the stage of dose titration, how often reviews and body-composition checks are needed, and whether added support such as nutrition guidance or facial and body contour planning is part of your plan. A written quote is given at consultation, after history, examination and metabolic screening. The consultation also decides whether medication is advised at all. If you do not meet the criteria, you are told why and alternatives are discussed.
How quotes work at this practice: how we quote.
They are prescription-only medicines that need an eligibility assessment, titration and monitoring, and buying them without assessment carries real risk.
Appetite physiology returns when the medicine stops, so a maintenance and exit plan is designed from the start.
Weight loss medication in Singapore is prescription-only, and eligibility follows the indications on the product labels registered with the Health Sciences Authority, not a wish to lose weight. In broad terms, labelled use for weight management applies to adults in the obesity range, or in the overweight range when at least one weight-related condition is present, alongside a reduced-calorie diet and more physical activity. The table frames those situations in qualitative terms. It is an explanation and not a promise of a prescription: the doctor weighs history, examination, current medicines and risks, and may conclude that medication is not appropriate. If you do not qualify, you are told why and what the alternatives are.
| Situation | Position against registered labels | What the assessment does |
|---|---|---|
| Obesity range | Within labelled use for weight management, alongside diet and activity | Reviews history and screening, then decides whether medication, and which, is appropriate |
| Overweight range with a weight-related condition | Within labelled use where the condition is present and documented | Checks the condition, current medicines and risks before any prescription |
| Overweight range without a weight-related condition | Outside the usual labelled use | Discusses a lifestyle programme and alternatives; medication is not the default |
| Below the overweight range | Not within labelled use for weight management | Says so plainly; a cosmetic-only goal does not qualify |
| Type 2 diabetes | Some products carry a diabetes registration instead | Physician or endocrinology review; the choice follows the registered indication |
Monitoring starts before the first dose. The baseline is a medical history, an examination, metabolic screening and body composition, because the starting point decides which risks need watching and gives later reviews something to be compared against. Thyroid, pancreas, gallbladder and stomach history, current medicines (particularly diabetes treatment), pregnancy plans and any history of an eating disorder are all asked about, since each changes whether a prescription is appropriate and how it is made. Tirzepatide can make oral contraceptives less reliable around the start and after dose increases, so contraception is part of the conversation too. Anything that makes the medicine unsuitable is better found here than after the first injection.
Once treatment begins, the dose is raised in steps, and each step is a review point. Weight is tracked, but so is body composition, because the aim is to protect muscle while weight falls, and protein intake and resistance training are checked alongside. Side effects are reviewed at each step: nausea, reflux and constipation are common early and are managed by pacing the dose. Hydration and food tolerance are noted. Signs that need same-day contact, such as severe or persistent abdominal pain, repeated vomiting, or yellowing of the skin or eyes, are explained in advance so that nobody has to guess.
Monitoring also looks ahead. Appetite physiology returns when the medicine stops, so maintenance and an exit plan are reviewed along the way rather than left to the end. Changes in the face and skin during weight loss are noted at follow-up, and a pause or a change of plan is considered if the medicine is not suiting you. Anyone planning a procedure under sedation or general anaesthetic should tell the team beforehand, because slowed stomach emptying is relevant to anaesthetic safety. The aim of all of this is a programme that is supervised from the first visit to the last, and that treats stopping as a planned step.
“Ozempic face” is a nickname for the change in the face that can follow rapid weight loss on GLP-1 medication. It describes the pace and amount of loss more than any direct effect of the medicine on the face. Facial fat sits in separate compartments that support the cheeks, temples, jawline and under-eyes, and these can empty faster than the skin is able to retract. The face may then look hollowed or older, with deeper under-eye shadows, jowls and new folds, even while the body is slimmer. The pattern is common enough to be discussed openly, and it is a reason to plan for the face at the same time as the weight, not afterwards.
Three things overlap: lost volume, skin laxity and a shift in proportion, because the face and neck do not lose fat at the same rate. They are separate problems with separate answers, which is why the face is mapped before any product is chosen. Supervised loss, with protein and resistance work to protect muscle, is part of the medical programme and is aimed at limiting the facial cost of the weight change. It cannot remove that cost, because the weight loss itself is the cause. What can be planned is the order of any later correction, and whether the face needs support rebuilt, tissue repositioned, skin tightened, or some combination of the three.
Restoring the face is its own discipline and is not part of the prescription. The order set out on the Ozempic face treatment page is to map the face, regenerate and reposition what remains, tighten, and add volume last and in smaller amounts, because filler alone does not address laxity or descent. If weight is still changing quickly, the honest advice may be to wait until it settles. Heavy skin excess is referred for surgical assessment. No product name is chosen until the examination has shown which of these problems is present, and the plan is written down before anything is booked.
They contain the same molecule — semaglutide. Ozempic is registered for type 2 diabetes; Wegovy is the formulation registered for weight management, with its own dosing schedule. Which, if either, is appropriate is a prescribing decision made on your medical picture.
They work differently: Wegovy acts on the GLP-1 receptor; Mounjaro acts on GLP-1 and GIP receptors. Published trials exist for both, but “better” is individual — response, tolerability, medical history and availability all matter, and that is what the assessment weighs. No honest clinic answers this question before examining you.
These are prescription-only medicines indicated at defined BMI thresholds, with lower thresholds when weight-related conditions are present. Eligibility is confirmed at medical assessment — and pursuing them below criteria, or through unregulated online sellers, carries real risk.
Gastro-intestinal effects — nausea, reflux, constipation — are common early and usually settle with careful titration. Gallbladder disease and pancreatitis are recognised, less common risks, and muscle loss is a practical concern the programme actively manages. A full discussion of risks against your history happens before any prescription.
Appetite signalling returns when the medication stops, and regain is common without a maintenance plan — that is physiology, not failure. This is why the exit strategy, habits and monitoring are part of the programme from the start.
Rapid weight loss deflates the structural fat that supports the face, which can read as sudden ageing. Slower, supervised loss with muscle preservation reduces it; where volume loss has already happened, restoration is planned by anatomy afterwards — see the dedicated Ozempic face page.
Not legally in Singapore without a prescription — and medicines from unregulated sources carry counterfeit and safety risks that are well documented. If a website will sell it to you without a doctor, that is the warning sign.
Prescription medicine pricing is not advertised. Cost depends on the medication, dose and programme structure, and is set out transparently at consultation.
According to HSA, GLP-1 medicines, including semaglutide, are prescription-only medicines approved to treat type 2 diabetes and/or weight management in people with obesity or overweight. Which product is registered for which use differs, and that is part of the prescribing decision.
Semaglutide and tirzepatide are given as a once-weekly injection under the skin, and liraglutide once daily, using a pre-filled pen. Patients are shown how to inject before starting, and the dose is increased in steps rather than started at full strength.
A medical weight loss programme begins with a doctor's assessment, including history, examination and metabolic screening, and may include a prescription medicine where eligibility criteria are met, with dose titration, side-effect monitoring and a plan for stopping. A slimming programme is usually a package of non-medical services such as diet coaching or body treatments, and cannot include prescription medicines. Both can support habits, but only a medical setting can assess weight-related conditions, decide whether medication is appropriate and manage its risks. Slimming products sold separately are a different concern: HSA has repeatedly warned about products found to contain undeclared medicines.
There is no fixed duration. Excess weight is treated as a long-term condition, and in clinical trials weight tended to return after the medicine was stopped, so how long someone stays on treatment is decided between doctor and patient and reviewed as the programme progresses. Some continue at a maintenance dose; others step down once habits, body composition and weight are stable, with closer monitoring afterwards. Side effects, pregnancy plans and any change in health also shape the decision. What matters is that stopping is planned rather than abrupt.
No. Weight loss injections such as semaglutide, liraglutide and tirzepatide are prescription medicines injected under the skin that act on appetite-regulating hormone pathways throughout the body, and they are aimed at overall weight in people who meet eligibility criteria. Fat-dissolving injections are a different category: products injected into a small area of fat to break it down locally, with no meaningful effect on body weight. For a discrete pocket of fat at a stable weight, the options discussed at this practice are set out on the fat freezing page.
The cost depends on the medicine prescribed, the dose stage, how often you are reviewed, and whether nutrition or contour planning is included. Because medication is prescription-only and decided at assessment, a written quote is given at consultation after your history and screening, and the consultation also decides whether medication is advised at all.
It can be worthwhile for adults who meet eligibility criteria, are ready for supervised titration and follow-up, and want a plan for maintenance. It is not suited to people seeking a quick cosmetic change below the criteria, those who are pregnant, or anyone unwilling to be monitored. Assessment decides which group you are in.
Its effect on appetite generally lasts only while it is taken, because appetite physiology returns when the medicine stops. How long someone stays on treatment depends on response, tolerance, health goals and the maintenance plan. No duration is promised; review timing and the plan for stopping are set at consultation and revisited at follow-up.
Common early effects are nausea, reflux and constipation. Muscle can be lost along with fat unless protein and resistance training are planned, and rapid weight loss can thin the face. Gallbladder problems and pancreatitis are recognised, less common risks. Appetite returns after stopping, and the medicine needs ongoing supervision and cost.
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Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 7 October 2026 · Editorial policy