If you've ever lived with obesity, chances are you've spent a whole lot of time, effort and stress trying to change your situation- maybe going around in circles for years where you're able to lose a bit but not keep it off. It's incredibly demoralising and frustrating, and you've probably found yourself looking at thinner people and wondering why they aren't battling things in the way that you are. This is because obesity isn’t a lifestyle choice or a matter of willpower, it's a recognised disease. A disease is generally defined as a condition that 'impairs normal function, has identifiable signs or symptoms, and increases risk of harm or complications'. Obesity fits this definition, because it disrupts normal regulation of appetite and energy, and raises the risk of conditions like type 2 diabetes, heart disease and certain cancers. There are lots of reasons as to why people become obese- and once you're at that point, the body works hard to defend its highest weight. It's the reason why most people regain the pounds they've lost again after dieting, even if they’ve done everything right and worked so hard to get there. Hormones push hunger up, slow metabolism down and make long term weight loss incredibly hard without extra support.
Why medication helps
For many people living with obesity, appetite and metabolism don’t behave in the same way as they do for someone naturally slim. Hunger hormones may be stronger, metabolism may run slower, and the normal GLP-1 response (this is the hormone that signals 'fullness' to your brain) after eating can be weak. Insulin resistance can add another layer of difficulty. Insulin resistance isn't the same as diabetes, it can happen years before a diabetes diagnosis so even if your numbers are in range, this could still be going on in your body. GLP-1 medications turn those signals back in your favour by reducing appetite, slowing digestion and keeping blood sugar steady. Mounjaro (tirzepatide) goes a step further by working on an extra hormone called GIP, which makes it even more powerful for many people.
The options right now
In the UK, the main weight loss injections are Wegovy (semaglutide) and Mounjaro (tirzepatide) which are once weekly injections. You can also get get Saxenda (liraglutide) which is a daily injection. You may have also heard of Ozempic, that’s semaglutide too but it's licensed here only for type 2 diabetes whereas Wegovy is the version licensed specifically for weight loss. Access through the NHS to weight loss medications is possible for some people, but it’s usually only available to those who hit a very specific criteria. Right now that's having a BMI of over 40 and 4 weight related conditions (such as high blood pressure and high cholesterol). As the years go on, the criteria will widen but right now, most people fund it themselves using a licensed online pharmacy.
Thinking about the cost
Weight loss injections aren’t a quick fix that you take for a few months and stop. Because obesity is a disease, it's not something that will just 'go away' for most people once they reach a healthy weight. Just like if you have thyroid disease for example, medication would keep your levels in range but once you stop, they'd climb back up because the root problem is still there. Obesity works the same way, treatment manages it, but the underlying condition doesn’t disappear. For this reason, many people who stop taking weight loss meds will rebound for the same reason that they gained weight it the first place, so it needs to be a long term solution for most (not everyone, but most people). This means that you do need to consider the cost over the long term, and whether this is something you'll be able to continue to finance. There are tools like Wegovy and Mounjaro price comparison sites that can help you to find the best prices, and switch around pharmacies if you need to to get the best deals. Cost is a big part of the decision, although many people do notice they spend less on food and takeaways due to the reduced hunger and can actually save money.
Who they’re for
Weight loss medications can be life changing, but they’re not for everyone. A clinician will look at your health history, any medicines you’re already on, and whether you’re planning pregnancy. They're not for a healthy person to shift a few points to look better in a swimsuit, they've been designed and clinically tested for obese people. If you've tried losing weight yourself and can't get it down or can't keep it off, these are well worth considering to improve your long term health.
Health benefits that matter
The benefits of these injections go beyond the number on the scales. Losing weight improves blood pressure, reduces risk of type 2 diabetes, helps with sleep apnoea and lowers strain on joints. GLP-1 medications themselves have also shown heart benefits in clinical trials, with semaglutide lowering the risk of major cardiovascular events in people who already had heart disease. Early studies suggest improvements in fatty liver too. It’s not just about appearance, the health gains that these meds can give you are real and significant.
What’s coming next
There’s a lot happening in the general space of weight loss medications, new treatments are already on the horizon. This includes retatrutide, which works on three different hormone pathways, and orforglipron which is a daily GLP-1 tablet. Both are still in trials as of now (August 2025) but could reach patients as soon as next year, giving even more options for people who need medical help with weight.
