You’ve probably heard the chatter about injectable weight-loss medications and found yourself wondering if they might hold the key to unlocking your health goals. Let’s be real — staying at a healthy weight can often feel like an uphill battle. Yet, the benefits of doing so are hard to ignore: From slashing the risk of diabetes and heart disease to reducing the chances of certain cancers and sleep apnea, the stakes are high. While the age-old duo of diet and exercise remains vital, these medications are stepping into the spotlight as a promising solution for those struggling with obesity or diabetes.
Do these injections actually deliver results? How do they stack up against one another? With names like Ozempic, Wegovy, and Zepbound dominating the headlines, how do you determine which one is the best fit for you? And now, with Mounjaro, a new contender stepping into the ring and creating a further stir, it is easy to get overwhelmed.
So, before you take the leap into the world of weight-loss injections, unpack the science, benefits, and possible risks of this treatment.
What are weight loss injections?
Samantha Goldstein, a UK-based endocrinologist breaks it down: “These weight loss injections are a class of medications that help people lose weight by targeting specific hormones, involved in hunger regulation, fat metabolism and blood sugar control. Most of these medications are administered through subcutaneous injections, meaning they are injected just under the skin. These injections are typically taken once a week, though some medications may require daily administration.”
Steps to calculate BMI:
Measure weight: Weigh yourself in kilograms (kg).
Measure height: Measure your height in meters (m). If your height is in centimeters, convert it to meters by dividing by 100 (e.g., 170 cm = 1.70 m).
So, who is it for? “These drugs are normally prescribed to those who are struggling with obesity, or have a body mass index (BMI) over 30, or those who with a BMI of 29 or higher, or battling weight-related health conditions such as Type 2 diabetes, hypertension or sleep apnea,” she explains. Goldstein adds, “ These weight loss injections are a part of the comprehensive treatment plan, which includes diet and exercise, and helping people lose
How do these weight-loss injections work?
As she explains, these injections work by mimicking the actions of hormones that regulate appetite, food intake, and glucose metabolism. The two most commonly targeted hormones are:
GLP-1 (glucagon-like peptide-1): A hormone that helps regulate blood sugar and suppresses appetite by slowing down the rate at which food leaves the stomach.
GIP (glucose-dependent insulinotropic polypeptide): Another hormone involved in insulin release and appetite regulation, playing a role in promoting feelings of satiation.
By mimicking these hormones, weight loss injections reduce appetite and make people feel far more satiated with smaller meals. As a result, they tend to consume fewer calories, which leads to weight loss over time. Additionally, some of these medications improve blood sugar control, which is especially beneficial for individuals with Type 2 diabetes.
The popular weight-loss injections:
There are several injectable medications currently approved for weight loss. The most widely used include:
1. Wegovy (Semaglutide)
Mechanism: Wegovy is the brand name for the medication semaglutide, which is used for chronic weight management in adults who are obese, or overweight. It is a GLP-1 receptor that helps regulate appetite and caloric intake, leading to significant weight loss when combined with a reduced-calorie diet and increased physical activity.
Effectiveness: According to a 2021 study, published in the US-based medical journal New England Journal Of Medicine, this phase 3 trial involved 1,961 adults with obesity or overweight and assessed the efficacy of semaglutide 2.4 mg. Participants received either the drug or a placebo alongside lifestyle interventions. The results showed that those treated with semaglutide lost an average of 15.3 per cent of their body weight over 68 weeks, compared to 2.6 per cent in the placebo group.
Target audience: It has been approved for individuals with a BMI of 30 or more or a BMI of 27 with weight-related health conditions.
2. Saxenda (Liraglutide)
Mechanism: Saxenda, is the brand name for the medication liraglutide, which is used for chronic weight management. Similar to semaglutide (Wegovy), Saxenda is a GLP-1 receptor agonist that helps regulate appetite and caloric intake, leading to weight loss when combined with a reduced-calorie diet and increased physical activity.
Effectiveness: A 2015 study published in the New England Journal of Medicine studied 3,731 participants with obesity or overweight and assessed the efficacy of liraglutide 3.0 mg. The participants received either the drug or a placebo alongside lifestyle interventions. The study found that those treated with liraglutide lost an average of 8.0 per cent of their body weight over 56 weeks compared to 2.6 per cent in the placebo group.
Target audience: It has been prescribed to adults and adolescents aged 12 and older who are overweight or obese and have related health conditions.
3. Mounjaro (Tirzepatide)
Mechanism: Tirzepatide works by mimicking both GLP-1 and GIP hormones, making it a dual-action drug that helps regulate appetite and improve insulin sensitivity.
Effectiveness: In the 2022 study published in the UK-based journal Diabetes Care, tirzepatide was compared to semaglutide in people with Type 2 diabetes. Tirzepatide showed superior weight loss, with participants losing an average of 15.0 kg (33.1 lbs) over 72 weeks compared to semaglutide.
Target audience: Initially approved for diabetes management, it is often prescribed off-label for weight loss due to its powerful dual-action mechanism.
The buzz around tirzepatide
Originally designed to treat Type 2 diabetes, this injectable medication is now creating a stir, for the potential it holds. It has been hailed as a ‘game-changer’, promising results and with claims of people shedding pounds like never before. For starters, tirzepatide, which is sold under the brand name Mounjaro and also Zepbound in some countries, it affects feelings of hunger and fullness, as well as changing how the body processes food, explains Lamya Kamal, a Dubai-based family medicine specialist and Zeenat Naseeb Abdul Wahid, Consultant Endocrinology, Medcare Hospital Sharjah.
How it works:
As the specialists explain, tirzepatide unlocks two critical pathways in your body’s weight management system. It works by mimicking the effects of two powerful hormones — GLP-1 and GIP — which naturally regulate appetite, food intake, and blood sugar. Normally, when you eat, your body releases these hormones to signal fullness and help control blood sugar. However, Tirzepatide cranks this up a notch. By amplifying the effects of GLP-1 and GIP, it helps you feel satisfied with smaller portions, leading to reduced food intake and gradual weight loss.
It acts on the appetite center situated in the hypothalamus and results in reduced appetite. It also causes delayed gastric emptying and increases satiety...
Not only that, tirzepatide also slows the emptying of your stomach and improves how your body processes sugar. The result? You eat less, feel fuller for longer, and enjoy better control over your blood sugar — making it a powerful tool for weight loss and overall health.
Elaborating further, Wahid says, “It acts on the appetite center situated in the hypothalamus and results in reduced appetite. It also causes delayed gastric emptying and increases satiety.” And so, your craving for certain kind of foods like sweets and fatty foods is reduced.
Why is it considered different from other weight-loss injections?
As Hala Zakaria, Researcher at Zone Health explains, tirzepatide targets two hormone receptors — GLP-1 and GIP — while semaglutide focuses solely on GLP-1. This dual-action approach is believed to contribute to tirzepatide's slightly superior weight loss results observed in clinical trials.
In fact, studies such as a 2023 study published in the JAMA Network journal, revealed that participants using tirzepatide lost an impressive average of 25 per cent of their body fat within the first year of treatment. Yet as he says, keep in mind that this remarkable result is achieved in conjunction with lifestyle counseling, encouraging a healthy, reduced-calorie diet, around 500 calories less per day, and at least 150 minutes of physical activity each week.
In comparison, those using semaglutide saw an average weight loss of about 15 per cent in the same timeframe, also supported by a reduced-calorie diet and increased exercise .
For someone weighing 150 kg, this difference could translate to losing 30 kg with tirzepatide versus 18 kg with semaglutide. It’s important to note that, with both medications, individual results may vary; some people might lose more than average, while others may lose less or not respond to the treatment at all.
The potential side-effects
The side effects of medications like tirzepatide and semaglutide are primarily due to their mechanisms of action and the physiological responses they trigger in the body. Wahid describes, “The common side-effects could be nausea, vomiting, diarrhea and constipation,” she says. These occur because these medications slow down gastric emptying, which can lead to feelings of fullness, nausea, or discomfort, especially when starting treatment or increasing the dose.
Moreover, you need to take into account that each person's body reacts differently to medications due to factors such as genetics, pre-existing health conditions, and other medications being taken. Some individuals may experience more pronounced side effects, while others may have minimal or no side effects. Furthermore, they can influence multiple hormones involved in digestion and appetite regulation. The adjustments in these hormone levels can lead to side effects as the body adapts to the changes.
A rare side-effect includes the risk of pancreatitis. Some of these injections are contraindicated in patients with personal or family history of medullary thyroid cancer. Zakaria explains, "The inflammation of the pancreas can cause severe abdominal pain and kidney problems, particularly in people who become dehydrated. Additionally, allergic reactions, such as rash, itching, or swelling of the face or throat can occur in rare cases," she says. So, consult your healthcare provider before attempting any of these injections. Regular check-ups are crucial for monitoring your body's response to the medication and addressing any potential side effects promptly, adds Zakaria.
What are the best lifestyle practices to adopt while taking these injections for optimal results?
Keep in mind that these injections aren’t a magical solution: They work in conjunction with your lifestyle modifications, including a healthy diet and physical activity.
Zakaria elaborates, "It's important to focus on whole, nutrient-dense foods such as fruits, vegetables, whole grains, lean proteins, and healthy fats. A helpful strategy is to start meals with protein, which can stabilise blood sugar levels and allows the person to feel fuller for longer, lowering the chances of overeating. Protein also plays a crucial role in preserving muscle mass during weight loss, making it an essential part of a balanced diet," she says.
You need to engage in physical activity and resistance training to maintain muscle mass. And of course, a good sleep and stress management is always crucial for weight loss, explain the specialists.
The lifestyle changes include healthy diet and physical activity, which are mainly about reducing carbohydrate portions - rice, pasta, bread, increasing protein intake to feel full for longer hours, and maintain muscle mass especially when you are on weight loss medication, increasing intake of fruits and vegetables, small amounts of dairy products, nuts and olive oil.
As the specialists advise, even if you lose weight by using the injections, your habits ultimately define the success in a weight journey. Stopping the injections could result in the insulin resistance coming back, and if you do not engage in better diet and exercise, you could experience weight gain again. Kamal warns, “It is very important to study your habits and focus on your relationship with yourself – both mentally and physically. Focus on building sustainable habits, such as engaging in regular strength training exercises to preserve muscle mass, which in turn helps prevent metabolism from slowing down as you lose weight. “
Similarly, ensure that your diet is protein rich, as this will aid muscle retention and support metabolic health. It is important to balance protein, fat and carb intake, to enhance the medication’s effectiveness.
