For many years, people living with obesity were repeatedly advised to “eat less and exercise more.” While nutrition and physical activity remain essential, we now understand that obesity is a complex, chronic medical condition influenced by appetite hormones, genetics, metabolism, sleep, medications, psychological factors and the surrounding environment.

This understanding has led to the development of medicines that act on the biological systems controlling hunger, fullness and food intake.

The newer weight-loss medicines—particularly semaglutide, tirzepatide and oral GLP-1 medicines—can produce considerably greater weight reduction than older treatments. However, they must be prescribed responsibly, combined with lifestyle measures and monitored medically.

Who May Be Considered for Weight-Loss Medication?

In adults, prescription weight-management medicines are generally considered for people with:

• A body mass index, or BMI, of 30 kg/m² or above, classified as obesity; or
• A BMI of 27 kg/m² or above along with a weight-related medical condition such as type 2 diabetes, hypertension, abnormal cholesterol, fatty liver disease or obstructive sleep apnoea.

These medicines are intended to accompany a reduced-calorie nutritional plan, physical activity and behavioural support. They are not substitutes for these measures.

BMI is only one part of the assessment. A doctor should also evaluate waist circumference, metabolic health, previous attempts at weight reduction, eating behaviour, current medications, pregnancy plans and the presence of medical complications.

How Do the Newer Medicines Work?

Many newer weight-loss medicines act on a naturally occurring intestinal hormone called glucagon-like peptide-1, or GLP-1.

GLP-1 medicines can:

• Reduce hunger and food cravings
• Increase the feeling of fullness after eating
• Decrease calorie intake
• Improve blood-sugar regulation
• Delay stomach emptying to varying degrees

Tirzepatide acts on both the GLP-1 and GIP receptors, whereas semaglutide and orforglipron primarily act on the GLP-1 receptor.

1. Tirzepatide

Weight-management brand in the United States: Zepbound
Diabetes brand: Mounjaro

Tirzepatide is a once-weekly injection that activates both the GLP-1 and GIP receptors. It is approved by the US FDA for adults with obesity or adults with overweight who have at least one weight-related medical condition.

In the major study involving adults without diabetes, participants receiving the highest approved dose lost an average of approximately 18% of their starting body weight over 72 weeks, compared with substantially less weight reduction in the placebo group. Individual results vary considerably.

Tirzepatide has also been approved in the United States for treating moderate-to-severe obstructive sleep apnoea in adults with obesity when used with dietary modification and physical activity.

Important clarification about Mounjaro and Zepbound

Mounjaro and Zepbound contain the same active ingredient—tirzepatide—but their approved indications and brand labelling may differ between countries.

A medicine being approved for diabetes under one brand does not automatically mean that the same brand is approved specifically for obesity. Doctors and patients should verify the locally approved indication rather than relying on social-media information.

2. Semaglutide Weekly Injection

Weight-management brand: Wegovy
Common diabetes brand: Ozempic

Semaglutide is a GLP-1 receptor agonist. Wegovy injection is administered once weekly and is approved for chronic weight management in eligible adults.

In a major adult obesity study, participants receiving semaglutide 2.4 mg lost an average of approximately 14.9% of their starting body weight over 68 weeks, compared with about 2.4% among those receiving placebo.

Wegovy injection is also approved in the United States for adolescents aged 12 years and above with obesity. In addition, it is approved to reduce major cardiovascular events such as cardiovascular death, heart attack and stroke in adults who have established cardiovascular disease together with overweight or obesity.

Wegovy in India

Wegovy was commercially launched in India in June 2025. CDSCO records also show approvals during 2026 for semaglutide injections specifically indicated for chronic weight management in eligible adults.

In May 2026, CDSCO records listed Wegovy for weight management in adolescents aged 12 years and above with obesity and body weight above 60 kg, subject to appropriate treatment assessment and monitoring.

Patients should use only an approved product obtained through a reliable pharmacy with proper storage and a valid prescription.

3. Higher-Dose Semaglutide: Wegovy HD

In March 2026, the US FDA approved a higher 7.2 mg weekly dose of semaglutide injection, known as Wegovy HD, for certain adults with obesity or overweight accompanied by a weight-related condition.

In an obesity study, average weight reduction after 72 weeks was approximately:

• 18.8% with semaglutide 7.2 mg
• 15.5% with semaglutide 2.4 mg
• 3.9% with placebo

The higher dose also produced more gastrointestinal adverse effects and a greater frequency of altered skin sensations in some patients. It should therefore not be viewed as automatically better for every patient.

Availability and regulatory approval of this higher dose outside the United States may differ.

4. Oral Semaglutide for Weight Management

Until recently, the obesity dose of semaglutide was available primarily as an injection. In December 2025, the US FDA approved Wegovy tablets for chronic weight management in eligible adults.

The oral formulation is taken once daily and is different from lower-dose oral semaglutide products used for diabetes.

In the weight-management trial, participants receiving the Wegovy tablet had an average weight reduction of approximately 13.6% after 64 weeks, compared with approximately 2.4% in the placebo group.

The tablet may be helpful for patients who are unwilling or unable to take injections. However, it still requires gradual dose escalation and adherence to the prescribed administration instructions.

Approval in the United States does not necessarily mean that oral Wegovy is currently approved or commercially available in India.

5. Orforglipron

US brand: Foundayo

Orforglipron is one of the most important recent developments in obesity treatment. The US FDA approved it in April 2026 for adults with obesity or adults with overweight and at least one weight-related condition.

Unlike peptide-based GLP-1 medicines, orforglipron is a small-molecule oral GLP-1 receptor agonist. It is taken once daily and may be taken with or without food.

In a 72-week study involving adults without diabetes, average weight reduction was approximately:

• 7.4% with the lower studied dose
• 8.3% with an intermediate dose
• 11.1% with the highest studied dose
• 2.1% with placebo

Among participants with type 2 diabetes, weight reduction was somewhat lower, reaching approximately 9.6% with the highest dose.

Foundayo is not currently approved for children, and its approval and availability in India must be checked separately.

6. Liraglutide

Weight-management brand: Saxenda

Liraglutide was one of the first GLP-1 medicines approved specifically for chronic weight management. Unlike semaglutide and tirzepatide, it is administered as a daily injection.

Although average weight reduction is generally lower than that seen with newer weekly medicines, liraglutide remains an established option for selected patients.

The US FDA has approved Saxenda for:

• Eligible adults with obesity or overweight
• Adolescents aged 12 years and above with obesity who weigh more than 60 kg

It must be combined with dietary modification and physical activity.

What About Older Approved Weight-Loss Medicines?

Several non-GLP-1 medicines remain approved for weight management, including:

• Orlistat
• Naltrexone with bupropion
• Phentermine with topiramate

These medicines act through different pathways and may still be appropriate when GLP-1 medicines are unsuitable, unavailable, poorly tolerated or unaffordable. FDA documents continue to list these medicines among approved pharmacological options for weight management.

The choice should be based on the patient’s medical history, eating pattern, cardiovascular status, mental-health history, other medications, pregnancy potential and treatment goals.

Are Ozempic and Mounjaro Weight-Loss Medicines?

This is a common source of confusion.

Ozempic contains semaglutide and is primarily branded and approved for type 2 diabetes. Wegovy contains semaglutide in a formulation and dosing programme approved for chronic weight management.

Similarly, Mounjaro contains tirzepatide and is commonly labelled for type 2 diabetes, while Zepbound is the US weight-management brand of tirzepatide.

Doctors may sometimes prescribe medicines outside their formally approved indication, which is known as off-label use. However, patients should not self-medicate or assume that different brands and dose strengths are interchangeable.

What Side Effects Can Occur?

The most common adverse effects of GLP-1 and GIP/GLP-1 medicines involve the digestive system:

• Nausea
• Vomiting
• Diarrhoea
• Constipation
• Abdominal discomfort
• Indigestion
• Reduced appetite

These effects are often more noticeable when treatment begins or when the dose is increased. Gradual dose escalation helps improve tolerability.

Less common but clinically important problems can include:

• Gallstones or gallbladder inflammation
• Pancreatitis
• Dehydration and kidney injury following persistent vomiting or diarrhoea
• Severe gastrointestinal intolerance
• Low blood sugar when combined with insulin or sulfonylureas
• Worsening of diabetic retinopathy in some patients with diabetes
• Allergic reactions
• Retained stomach contents around anaesthesia or deep sedation

Patients should inform their surgeon and anaesthetist that they are taking a GLP-1 medicine before any planned procedure.

Who Should Avoid or Use These Medicines With Extra Caution?

GLP-1 medicines are generally contraindicated in people with:

• A personal or family history of medullary thyroid carcinoma
• Multiple Endocrine Neoplasia syndrome type 2
• A serious previous allergic reaction to the medicine

Additional caution is required in people with severe gastroparesis, previous pancreatitis, gallbladder disease, significant dehydration risk, diabetic retinopathy or concurrent insulin treatment.

These medicines are not intended for use during pregnancy. Women planning pregnancy should discuss when the medicine must be discontinued with their treating doctor.

Can These Medicines Cause Muscle Loss?

Any substantial weight reduction can involve the loss of both body fat and some lean body mass. Therefore, treatment should not focus only on the number displayed by the weighing scale.

A proper weight-management programme should include:

• Adequate dietary protein
• Resistance or strength training
• Regular physical activity
• Monitoring of nutritional intake
• Assessment of muscle strength, particularly in older adults
• Correction of vitamin or mineral deficiencies where present

Extremely low food intake, prolonged vomiting or rapid unsupervised weight loss can increase the risk of weakness, nutritional deficiency and muscle loss.

Are These Medicines Suitable for Children?

Weight-loss medicines should never be given to a child merely because the child appears “heavy.”

Children and adolescents must be assessed using age- and sex-specific BMI percentiles rather than adult BMI limits. Evaluation should also include growth pattern, pubertal stage, family history, blood pressure and screening for diabetes, lipid abnormalities, fatty liver disease and sleep apnoea.

Among the newer medicines, semaglutide injection and liraglutide have approvals for selected adolescents aged 12 years and above with obesity. Tirzepatide, oral semaglutide and orforglipron do not currently have equivalent general paediatric weight-management approvals in the United States.

Medication in an adolescent should form part of a comprehensive programme involving the child, parents, paediatrician, dietitian and, where appropriate, a paediatric endocrinologist.

Why Medical Supervision Is Essential

Before prescribing a weight-loss medicine, the doctor may need to assess:

• Height, weight, BMI and waist circumference
• Blood pressure
• Blood glucose and HbA1c
• Lipid profile
• Liver and kidney function
• Thyroid history
• Current medications
• Pregnancy plans
• Symptoms of sleep apnoea
• Eating disorders or problematic eating behaviour
• Previous pancreatitis or gallbladder disease

Follow-up is required to assess weight response, adverse effects, hydration, nutrition, blood sugar and whether treatment remains beneficial.

These medicines are approved for chronic weight management. They should not be used as brief “slimming courses” before a wedding, holiday or social event.

Beware of Counterfeit and Unapproved Products

The popularity of semaglutide and tirzepatide has led to the sale of counterfeit, unapproved and improperly compounded products.

The FDA has reported dosing errors, hospitalisations, incorrect concentrations, fraudulent labels and adverse events associated with some compounded or illegally marketed GLP-1 products. It has also warned against products containing semaglutide salt forms and products falsely labelled for “research use.”

Patients should never purchase these medicines through social-media sellers, beauty clinics, gyms or unknown websites.

Medicines Still Under Investigation

Several medicines appearing in news reports and social-media discussions remain investigational or may not yet be approved in a particular country.

For example, retatrutide has attracted attention because of promising clinical-trial results, but patients should not buy products claiming to contain retatrutide. The FDA has specifically warned about unapproved semaglutide, tirzepatide and retatrutide products marketed directly to consumers.

“Promising in a clinical trial” and “approved for routine medical use” are not the same thing.

Medical Disclaimer:
This article is intended for general health education and does not replace an individual medical consultation. Regulatory approvals, brand names, indications and availability differ between countries and may change over time. Weight-loss medicines should be used only after evaluation and prescription by a qualified medical professional.