GLP-1 Weight Loss Injections in Singapore: What Patients Need to Know Before Starting
Few medical developments have generated as much conversation in recent years as GLP-1 receptor agonists. The drugs — which include semaglutide (available in Singapore under various formulations) — have demonstrated weight loss outcomes in clinical trials that were once considered achievable only through surgery. And they’re increasingly accessible through medical clinics across Singapore.
But with visibility comes misinformation. Patients come to consultations with questions ranging from basic (“how does it work?”) to nuanced (“will I lose muscle?”) to practical (“what happens when I stop?”). This article addresses those questions directly.
GLP-1 stands for glucagon-like peptide-1. It’s a hormone naturally produced in the gut in response to eating. When food enters the small intestine, GLP-1 is released and acts on multiple tissues:
- — stimulating insulin secretion in a glucose-dependent way (only when blood sugar is elevated)
- — slowing gastric emptying, which delays the feeling of hunger
- — acting on appetite-regulating centres in the hypothalamus to reduce appetite and food-seeking behaviour
GLP-1 receptor agonist drugs mimic and extend the effects of natural GLP-1. They bind to GLP-1 receptors throughout the body and produce a more potent and prolonged version of the natural hormone’s effects.
The result: significantly reduced appetite, reduced food intake, slower stomach emptying, and progressive weight loss.
The clinical trial evidence for GLP-1 receptor agonists in weight management is substantial.
The STEP trials for semaglutide — the GLP-1 agent most widely discussed — showed average weight loss of 14.9% of body weight over 68 weeks in patients without diabetes, compared to 2.4% in the placebo group [1]. This is a level of weight loss that approaches what has historically been associated with bariatric (weight loss) surgery.
Follow-up studies have examined cardiovascular outcomes, with the SELECT trial demonstrating that semaglutide reduces major cardiovascular events in overweight or obese patients with established cardiovascular disease — suggesting benefits beyond weight loss alone [2].
“The evidence base for GLP-1 receptor agonists is genuinely strong,” says Dr. Low Chai Ling, Medical Director, SW1 Clinic. “These are not supplements or gimmicks — they are prescription medications with real pharmacological mechanisms, studied in large randomised trials. What patients need is accurate information and proper medical supervision, not hype in either direction.”
In Singapore, GLP-1 receptor agonists are prescribed medications, requiring a doctor’s assessment. They are appropriate for:
- Patients with BMI ≥27 with at least one weight-related health condition (hypertension, type 2 diabetes, dyslipidaemia, obstructive sleep apnoea)
- Patients with BMI ≥30
- Patients who have made sustained lifestyle changes without achieving adequate weight loss
- Under a doctor’s supervision and as part of a comprehensive weight management plan
They are not prescribed for patients who are already at a healthy weight, and they are not an alternative to the lifestyle foundations of weight management — diet and physical activity.
At SW1 Clinic, GLP-1 treatment is available through the programme — a medically supervised weight management protocol.
The medication is self-administered via a small subcutaneous injection, typically once weekly. Treatment begins at a low dose and is gradually increased over weeks to months to reach the maintenance dose — a process called titration, which helps manage side effects.
Regular check-ins with the prescribing doctor are important to:
- Monitor weight loss progress
- Adjust dosing
- Screen for side effects
- Advise on nutrition and exercise support
GLP-1 medications are generally well-tolerated, but side effects — particularly gastrointestinal — are common, especially when doses are being titrated upward:
- — the most common side effect; typically most pronounced at the start of treatment or after dose increases; improves over time for most patients
- — less common; usually transient
- — reported in some patients
- — this is intended, but can occasionally become excessive
Serious adverse effects are rare but include pancreatitis and, in patients with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2, contraindication to use.
A thorough medical history and contraindication screening is performed before initiation of treatment.
One of the most frequently discussed concerns with rapid weight loss — including GLP-1-assisted weight loss — is the risk of losing lean muscle mass alongside fat.
Research has confirmed that a proportion of weight lost with GLP-1 agonists is lean mass rather than purely fat [3]. This is a genuine concern, particularly for patients who are already lean and those who are older (where muscle mass preservation is physiologically more important).
The clinical response to this concern includes:
Higher protein diets during active weight loss help preserve muscle mass. This should be discussed and monitored.
Regular strength training is the most evidence-supported intervention for preserving lean mass during caloric restriction and GLP-1-assisted weight loss.
“I counsel all my GLP-1 patients on resistance training from the start,” says Dr. Low Chai Ling. “The medication creates the caloric deficit. The resistance training tells the body to preserve muscle. These two components need to go together — one without the other produces suboptimal body composition outcomes.”
Clinical trial data shows that weight regain is common after discontinuing GLP-1 therapy. The STEP 4 extension trial showed that patients who discontinued semaglutide regained approximately two-thirds of their weight over the following year [VERIFY CITATION].
This reflects the underlying biology: GLP-1 receptor agonists act as pharmacological support for appetite regulation. When that support is withdrawn, the underlying appetite and metabolic drivers that contributed to weight gain re-emerge.
This makes clear that GLP-1 treatment is most effective as a component of a sustained lifestyle change — not as a standalone or temporary solution. Long-term prescribing decisions should be made in consultation with your doctor, accounting for ongoing risk-benefit assessment.
Wei Xian, 44, had been managing type 2 diabetes and obesity for several years. Despite sustained dietary efforts, her weight had remained significantly above healthy range. After consultation, she was started on GLP-1 therapy alongside a supervised nutrition and resistance training programme.
Over nine months, she lost 16% of her initial body weight. Her blood glucose improved significantly. “What surprised me,” she said, “was how much the medication changed my relationship with food. The constant background hunger I’d lived with for years just — quietened. For the first time, making better choices felt possible.”
GLP-1 treatment is a significant medical intervention that deserves a thorough, informed consultation. At SW1 Clinic, that conversation includes a full health assessment, a discussion of expectations and realistic outcomes, and a plan for ongoing monitoring and lifestyle support.
Book a consultation at to find out whether GLP-1 treatment is appropriate for you.
[1] Wilding, J. P. H., Batterham, R. L., Calanna, S., et al. (2021). Once-weekly semaglutide in adults with overweight or obesity. , 384(11), 989–1002. [2] Lincoff, A. M., Brown-Frandsen, K., Colhoun, H. M., et al. (2023). Semaglutide and cardiovascular outcomes in obesity without diabetes. , 389(24), 2221–2232. [3] Wilding, J. P. H., et al. (2022). Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. , 24(8), 1553–1564.
