By Dr H. Guru Prasad
A new trend is changing the way people look at weight loss. From social media discussions and celebrity transformations to conversations in gyms and workplaces, weight-loss injections have become one of the most talked-about health topics. Many people are curious about medicines such as semaglutide and tirzepatide, which promise significant weight reduction while also helping control blood sugar levels. For some, these injections appear to offer an easy way to lose weight without strict dieting or exhausting exercise routines. Others are considering them because they have struggled with obesity or diabetes for years despite trying different treatments. The growing availability of more affordable versions in India has added to the interest. But are these injections suitable for everyone? Are they safe for long-term use? What happens when a person stops taking them? And can they really replace traditional diabetes medicines, healthy eating and physical activity? These are important questions because, although semaglutide and tirzepatide are major advances in modern medicine, they are not miracle weight-loss solutions. They are prescription medicines that must be used for the right medical reasons, at the right dose and under proper medical supervision. Understanding their benefits, limitations and possible risks is essential before deciding whether treatment is appropriate.
How do these injections work?
To understand these medicines, it helps to know how the body naturally controls hunger and blood sugar. After we eat, the intestine releases hormones that send signals to the pancreas and brain. These hormones help the body release insulin, control blood sugar and regulate appetite. They also influence how quickly food moves from the stomach into the intestine. Semaglutide belongs to a group of medicines called GLP-1 receptor agonists. In simple terms, it acts like a natural hormone called GLP-1, which helps control blood sugar and appetite. It encourages the pancreas to release insulin when blood sugar is high, reduces the release of another hormone that raises blood sugar and slows down the movement of food from the stomach. This helps people feel full for longer and reduces hunger and food intake. Tirzepatide works in a similar way but acts on two natural hormone pathways, called GIP and GLP-1. By targeting both, it improves blood sugar control and helps reduce appetite and body weight. Both medicines are available as once-weekly injections. Semaglutide is also available in tablet form for certain diabetes indications. Although these medicines have some similar effects, they are not identical. Their doses, approved uses and treatment plans differ. The formulation prescribed for diabetes should not automatically be considered interchangeable with a formulation intended for weight management. The choice of medicine depends on the patient's health, medical history, treatment goals and the specific product's approved indication.
Who actually needs these injections?
One of the biggest misconceptions is that anyone who wants to lose a few kilograms can take these injections. That is not how these medicines should be used. They are primarily prescribed to eligible adults with type 2 diabetes or obesity, and in certain cases, people who are overweight and have related health problems. The exact eligibility criteria depend on the medicine, its approved indication and the patient's medical condition. For people with type 2 diabetes, these medicines can be particularly useful when blood sugar levels are not adequately controlled with existing treatment. They may be especially beneficial for patients who also have excess weight, high blood pressure or other metabolic problems. For obesity, doctors may consider medication when lifestyle changes alone have not achieved sufficient or lasting weight reduction. In India, doctors must also consider population-specific BMI standards. BMI, or Body Mass Index, is calculated using a person's weight and height. For Asian Indians, a BMI of 23–24.9 is generally considered overweight and 25 or above indicates obesity. However, BMI alone does not determine whether someone needs medication. Waist circumference, body fat distribution, diabetes, blood pressure, cholesterol levels, fatty liver disease and sleep apnoea are also important. Indian clinical guidelines recommend considering weight-management medicines in selected patients at lower BMI levels than some international thresholds. However, the specific product's approved prescribing criteria must also be followed. For example, an adult with obesity and type 2 diabetes who is struggling to control blood sugar may benefit from one of these medicines. Similarly, someone with obesity and conditions such as high blood pressure or sleep apnoea may be considered for treatment after a medical assessment. On the other hand, a person who is only slightly overweight and wants to lose a few kilograms for cosmetic reasons may not need these medicines. The aim should be to improve health, reduce the risk of diabetes-related and obesity-related complications and improve quality of life, not simply achieve a particular number on the weighing scale.
Who should avoid them?
Despite their benefits, these injections are not suitable for everyone. A doctor's assessment is essential before treatment. Women who are pregnant should not use these medicines for weight loss. Those planning pregnancy should discuss stopping treatment in advance. Semaglutide is generally stopped at least two months before a planned pregnancy. Tirzepatide also requires specific pregnancy-related precautions, which should be discussed with the treating doctor. These medicines should not be used during pregnancy, and breastfeeding recommendations must be checked against the individual product's prescribing information. People with a history of serious allergic reactions to these medicines should avoid them. Those with a personal or family history of medullary thyroid cancer or a condition called Multiple Endocrine Neoplasia type 2 (MEN2) must discuss this with their doctor. These are important warnings in the prescribing information for these medicines, although the exact contraindications should be checked against the particular product label. People who have had pancreatitis, gallbladder problems or serious digestive disorders need careful assessment. Patients with severe gastroparesis, a condition in which food moves very slowly out of the stomach, may not be suitable because these medicines slow stomach emptying further. People with kidney problems also need attention, particularly if they are prone to dehydration from vomiting or diarrhoea. These medicines are not treatments for type 1 diabetes or diabetic ketoacidosis. Doctors must also review other medicines a patient is taking. Those already using insulin or certain diabetes tablets may need adjustments to avoid low blood sugar. The important point is that these injections should never be started simply because a friend, colleague or family member has experienced weight loss after using them.
What are the side effects?
Like any medicine, semaglutide and tirzepatide can cause side effects. The most common problems involve the stomach and digestive system. Nausea is particularly common during the early stages of treatment or when the dose is increased. Some people may also experience vomiting, diarrhoea, constipation, bloating, acidity and abdominal discomfort. These symptoms are often mild to moderate and may improve as the body adjusts to the medicine. Doctors usually start with a low dose and increase it gradually to help reduce these problems. Eating smaller meals, avoiding very oily or heavy foods, eating slowly and drinking enough water may help. However, persistent vomiting, severe abdominal pain or inability to drink fluids should not be ignored. There are also some less common but potentially serious complications.
- Pancreatitis: This is inflammation of the pancreas. Severe and persistent abdominal pain, sometimes spreading towards the back and accompanied by vomiting, requires immediate medical attention.
- Gallbladder problems: Rapid weight loss can increase the risk of gallstones and gallbladder inflammation. Severe pain in the upper right side of the abdomen, fever or yellowing of the eyes and skin should be evaluated promptly.
- Dehydration and kidney problems: Repeated vomiting or diarrhoea can cause dehydration. This may affect kidney function, especially in people who already have kidney disease.
- Low blood sugar: These medicines do not usually cause low blood sugar when used alone. However, the risk increases when they are combined with insulin or certain other diabetes medicines. Warning signs include sweating, shaking, dizziness, hunger, confusion and a fast heartbeat.
- Eye complications: In some people with diabetes, a rapid improvement in blood sugar levels can temporarily worsen existing diabetic retinopathy, which is damage to the blood vessels in the eyes. Patients with existing eye problems need appropriate monitoring.
Serious allergic reactions are also possible, although uncommon. Patients should not assume that severe side effects are a normal part of treatment. Any unusual or persistent symptoms should be reported to the treating doctor.
What happens when you stop the injections?
This is one of the most important questions people should ask before starting treatment. Many people believe that once they reach their target weight, they can simply stop the injections and continue enjoying the same results. Unfortunately, weight regain is common after stopping these medicines. Obesity is not simply a result of eating too much or exercising too little. It is a long-term medical condition influenced by genetics, hormones, metabolism, appetite, sleep and lifestyle. When a person loses weight, the body may respond by increasing hunger and reducing energy expenditure. These natural responses can make it difficult to maintain weight loss. Semaglutide and tirzepatide help control appetite and food intake while a person is taking them. Once treatment stops, hunger may return and body weight can gradually increase. Clinical research has demonstrated this. In the STEP 1 study extension, people who stopped semaglutide regained around two-thirds of the weight they had lost over the following year. Similarly, the SURMOUNT-4 study found that people who stopped tirzepatide regained an average of 14% of their body weight during the 52 weeks after switching to a placebo, while those who continued treatment maintained and increased their weight loss. These findings do not mean that everyone will regain all the weight they have lost. Results vary from person to person. However, they clearly show why obesity treatment needs a long-term plan. For people with diabetes, stopping treatment may also lead to an increase in blood sugar levels if another effective treatment is not introduced. Therefore, patients should never discontinue these medicines on their own. The doctor may recommend continuing treatment, changing the dose or moving to another suitable treatment depending on the patient's progress. The important message is that these injections should not be treated as a short-term cosmetic solution. For many patients, managing obesity requires long-term medical support.
Are cheaper generic injections safe?
The availability of more affordable medicines has become an important development in India's diabetes and obesity treatment market. With the introduction of lower-cost semaglutide formulations, treatment may become more accessible to people who previously found branded injections expensive. This is particularly relevant in India, where the cost of long-term treatment can be a major concern for patients. However, a lower price does not automatically mean that a medicine is unsafe. A genuine, properly approved generic medicine that meets the required quality standards can be a suitable treatment option. At the same time, not every cheaper product available in the market is necessarily a genuine or approved generic. Patients must check whether the product has the required regulatory approval, whether it is manufactured by a legitimate pharmaceutical company and whether it has been obtained through an authorised pharmacy. The label should clearly mention the medicine's name, strength, batch number, manufacturing details and expiry date. Patients should also follow the storage instructions. It is important to remember that semaglutide and tirzepatide are two different medicines. They cannot be substituted for one another simply because both are used for diabetes and weight management. The regulatory status and approved uses of products containing each medicine must be checked separately. The availability of a lower-cost alternative should be discussed with the treating doctor rather than decided independently. Affordability is important, but quality, correct dosage and patient safety must always come first.
Why buying injections online can be risky
The popularity of these medicines has also created opportunities for unauthorised sellers. Some websites and social media accounts advertise weight-loss injections with promises of quick results. Others offer medicines at unusually low prices without asking for a proper prescription. This can be dangerous. There is no guarantee that a medicine purchased from an unverified seller is genuine. Counterfeit products may contain the wrong ingredients, incorrect strengths or harmful contaminants. Storage is another major concern. Many injectable formulations require refrigeration under specified conditions. If the medicine is exposed to unsuitable temperatures during transportation or storage, its quality may be affected. There is also the risk of incorrect dosing. These medicines are generally started at a low dose and increased gradually. Taking too much too soon can cause severe nausea, vomiting, dehydration and other complications. In March 2026, India's drug regulator, the Central Drugs Standard Control Organisation (CDSCO), intensified surveillance of the GLP-1 medicine supply chain following concerns about unauthorised sales and misleading promotions. Inspections included online pharmacy warehouses, retailers, wholesalers and weight-loss clinics. The message is clear: patients should obtain these medicines only against a valid prescription and through legitimate, regulated pharmacies. They should never buy injections through social media sellers or unverified websites. A consultation with a qualified medical specialist is essential before starting treatment. In India, patients should follow the applicable prescribing requirements and approved indications.
Do these injections replace diet and exercise?
Absolutely not. This is one of the biggest misunderstandings surrounding weight-loss injections. Semaglutide and tirzepatide can reduce hunger, help people eat smaller portions and support weight loss. However, they cannot replace a balanced diet, regular exercise or healthy daily habits. In fact, these medicines are intended to be used along with lifestyle changes. A balanced diet should include vegetables, fruits, pulses, whole grains, nuts, healthy fats and adequate protein. Reducing sugary drinks, highly processed foods and excessive calorie intake is equally important. Protein deserves special attention because people losing weight can lose muscle along with body fat. Adequate protein intake, combined with strength exercises, can help preserve muscle and maintain physical strength. Regular physical activity improves the body's ability to use insulin, supports heart health, helps control blood pressure and improves overall fitness. Adults should aim for at least 150 minutes of moderate physical activity every week, along with muscle-strengthening exercises on at least two days, depending on their health and physical ability. Walking, cycling, swimming and strength training are practical options. Even small changes, such as taking the stairs, walking after meals and reducing prolonged sitting, can make a difference. Good sleep and stress management also matter. Poor sleep and chronic stress can affect appetite, food choices and blood sugar control. The goal should not simply be to lose weight while taking an injection. It should be to build healthier habits that can be maintained over the long term.
Can they replace regular diabetes medicines?
Another common concern is whether people taking semaglutide or tirzepatide can stop their regular diabetes medicines. The answer is: not without medical advice. These medicines can significantly improve blood sugar control in many people with type 2 diabetes. In some cases, doctors may reduce the dose of existing medicines. However, this decision depends on blood sugar readings, HbA1c levels, kidney function, the duration of diabetes and the patient's overall health. Metformin, insulin and other diabetes medicines work in different ways. Some patients may need a combination of medicines to achieve good blood sugar control. Those taking insulin or medicines such as sulfonylureas may need closer monitoring because the combination can increase the risk of low blood sugar. It is particularly dangerous for patients who have been using insulin for several years to stop it suddenly after starting a weight-loss injection. Diabetes management involves much more than controlling body weight. Blood sugar, blood pressure, cholesterol, kidney function, heart health and eye health all need attention. Patients should continue their regular follow-up appointments and never change their diabetes medicines without consulting their doctor.
Why regular medical follow-up matters
Starting an injection is not the end of treatment. Regular medical follow-up is essential to ensure that it is working safely and effectively. Before prescribing these medicines, doctors generally assess weight, BMI, waist circumference, blood pressure, blood sugar and HbA1c. Depending on the patient's history, kidney function, liver health and cholesterol levels may also be checked. During treatment, the doctor monitors weight changes, blood sugar levels, side effects, hydration and nutritional intake. Patients with diabetes may also require regular eye examinations, especially if they already have diabetic retinopathy. Another important concern is inadequate nutrition. Since these medicines reduce appetite, some people may eat too little. This can lead to weakness, nutritional deficiencies and loss of muscle mass. A dietitian can help patients maintain a balanced diet while losing weight. In some cases, other specialists may also be involved in care. Patients should inform their doctor if they are planning surgery or a procedure requiring general anaesthesia or deep sedation. These medicines slow stomach emptying, which can affect the risk of complications during anaesthesia. The decision to pause treatment should be made by the treating doctor and anaesthesia team.
The right approach to diabetes and obesity treatment
Semaglutide and tirzepatide represent an important step forward in the treatment of type 2 diabetes and obesity. For the right patients, they can improve blood sugar control, support significant weight loss and help address several health problems associated with excess weight. But their benefits should not overshadow the need for responsible use. Not everyone who wants to lose weight needs an injection. Not every patient with diabetes is automatically a suitable candidate. Side effects, existing medical conditions, other medicines and long-term treatment plans must all be considered. The availability of more affordable medicines in India is encouraging, but patients must remain cautious about unverified products, online purchases and misleading claims. On World Diabetes Day, it is important to remember that managing diabetes and obesity is a long-term commitment. Modern medicines can make that journey easier for many people, but they work best when combined with healthy eating, regular physical activity, proper sleep and regular medical care. The real measure of success is not just how many kilograms a person loses, but how much better their overall health becomes. These injections can be valuable medical tools, but lasting results depend on the right treatment, responsible use and healthier lifestyle choices.
(Dr H. Guru Prasad is a Consultant Physician and Director of Internal Medicine at Renova Century Hospitals, Banjara Hills, Hyderabad, with over 24 years of experience in diagnosing and managing a wide range of medical conditions. His areas of expertise include diabetes management, cardiometabolic disorders, tropical medicine, infectious diseases, geriatric medicine, medical disorders during pregnancy, emergency and critical care, and clinical risk assessment. He also has experience in medical research, clinical trial applications and departmental leadership, with a strong commitment to evidence-based medicine, accurate diagnosis and comprehensive, patient-centred care.)
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