Prescription weight-loss injections: who’re they for?

Obesity is extra complicated than merely consuming an excessive amount of or exercising too little. According to Dr Bernard Tan, medical director at Bay Medical Clinic, it’s influenced by a mix of things, together with hormones that regulate urge for food and metabolism, genetics, sleep, stress, life-style habits and underlying medical situations. 

Reflecting this complexity, the World Health Organization (WHO) recognises weight problems as a continual illness slightly than merely a way of life challenge. 

“This is why some people struggle to lose weight,” explains Dr Tan. 

Left untreated, weight problems and extra weight may also elevate the chance of growing a variety of continual well being situations, together with Type 2 diabetes, hypertension, coronary heart illness and fatty liver illness, says Dr Tan.

“Obesity is also linked to conditions such as obstructive sleep apnoea and joint problems, which can affect quality of life.”

According to the National Population Health Survey, the proportion of Singapore residents dwelling with weight problems elevated from 10.5 per cent within the 2019 to 2020 survey to 12.7 per cent within the 2023 to 2024 survey. 

Healthy consuming, common train and sustainable life-style modifications stay the cornerstone of long-term weight administration, says Tan. 

But for some individuals dwelling with weight problems, life-style measures alone might not be sufficient. In such circumstances, medical doctors might contemplate prescription medicines, including injectable GLP-1-based therapies, as a part of a complete weight administration programme.

How do prescription weight-loss injections work?

According to Dr Tan, GLP-1, which stands for glucagon-like peptide-1, is a hormone naturally produced by the intestine after a meal to sign to the mind that an individual is full. It additionally prompts the pancreas to launch insulin, helps regulate blood sugar, slows abdomen emptying and reduces meals cravings.

Another hormone, GIP (glucose-dependent insulinotropic polypeptide), additionally stimulates insulin launch however performs a special function in how the physique makes use of and shops vitality.

Tirzepatide is a category of prescription remedy that mimics the actions of each GLP-1 and GIP. By activating each pathways, it helps regulate urge for food, enhance blood sugar management and assist weight reduction when used alongside life-style modifications. 

“Many prescription weight-loss medicines work by acting on the GLP-1 pathway alone,” notes Dr Tan. “Tirzepatide, however, works differently. It is a dual GIP and GLP-1 receptor agonist – meaning it activates the receptors for both hormones, mimicking their natural effects in the body.” 

Adds Dr Hoe Ying Min, medical director at Bay Medical Clinic: “By doing so, it leads to reduced appetite, increased feelings of fullness, fewer cravings and a lower overall calorie intake. A medical weight loss programme aims for a sustained caloric deficit over a period to achieve long-term, sustainable weight loss.”

Dr Hoe cites the Surmount-5 trial, a 72-week research involving 751 adults dwelling with weight problems that evaluated tirzepatide.

The research, revealed within the New England Journal of Medicine in May 2025, discovered that members receiving tirzepatide misplaced, on common, about 20 per cent of their physique weight over the course of the research.

She provides: “In addition to weight loss, the Surmount-1 trial also reported improvements in certain health measures, including blood sugar, blood pressure and cholesterol, in some patients receiving once-weekly tirzepatide. Individual responses to treatment may vary.”

However, remedy alone isn’t a silver bullet for weight problems as weight gain will eventually happen after treatment stops, says Dr Hoe.

“In the Surmount-4 trial, patients who were treated with tirzepatide for nine months subsequently stopped treatment for a year. On average, they regained about half the weight they had lost.”

She stresses: “Obesity is a chronic condition requiring long-term follow-up; the initial treatment with weight-loss injections need to be followed by lifestyle changes.”

Dr Tan advises overweight sufferers to first lose some extra weight earlier than they can train meaningfully, by climbing stairs, going for a run and so forth. “For some patients, prescription medication may support initial weight loss, making it easier to adopt sustainable lifestyle changes under medical supervision.”

Are prescription weight-loss injections best for you?

According to Dr Tan, such medicines are usually not supposed for people of regular weight who wish to shed a number of kilos.

He says prescription weight-loss injections are clinically indicated for adults with weight problems (a physique mass index, or BMI, of 30kg/m² or larger), or those that are obese (a BMI of 27kg/m² to 30kg/m²) and have obesity-related situations corresponding to excessive ldl cholesterol, Type 2 diabetes and obstructive sleep apnoea, following a health care provider’s evaluation.

According to the WHO’s conditional recommendations, GLP-1 therapies are prohibited for youngsters and adolescents beneath the age of 21, and there’s no security knowledge for pregnant and breastfeeding ladies.

Most sufferers expertise mild-to-moderate gastrointestinal uncomfortable side effects – corresponding to nausea, diarrhoea, constipation and bloating – particularly through the preliminary one to 2 months through the dose escalation interval, notes Dr Tan.

“In rare cases, patients may develop gallstones or inflammation of the gallbladder or pancreas due to the gallstones. These patients will experience severe abdominal pain and vomiting and will need to go to a hospital’s accident and emergency department immediately. This affects less than 1 per cent of patients.”

Cautions Dr Hoe: “Prescription weight-loss injections should be obtained only through registered healthcare professionals at licensed clinics. Patients should avoid buying medications from online sellers, friends, overseas agents or unverified sources.”

For those that don’t require medical therapy, Dr Tan recommends specializing in sustainable life-style habits as a substitute of drastic diets. 

He advises: “Try eating until you’re about 80 per cent full, cut back on sugary drinks and late-night suppers, and remember that every bit of physical activity counts – whether it’s taking the stairs, going for a walk or doing household chores. 

“Having a partner or friend to keep you accountable can also make the journey easier. Most importantly, aim for habits you can maintain over the long term rather than striving for perfection.”

Find out extra about Bay Medical Clinic’s doctor-supervised medical weight management programmes.

Disclaimer: This article is for instructional functions solely and isn’t medical recommendation. Individuals are beneficial to seek the advice of with their physician for acceptable therapy.