How does weight loss medication work?

In recent years, weight loss medications like Wegovy and Mounjaro have become increasingly visible in the media and on social platforms, leading many people to wonder how these medications work and whether they might be suitable for them. 

With so much information online, it can be difficult to separate the facts from the hype. So, how does weight loss medication actually work, and could it be the right option for you?

This guide explains how weight loss medication works, who it may be suitable for and what you can expect from treatment.

What is weight loss medication?

Weight loss medication refers to prescription treatments designed to help people with a high body mass index (BMI) lose weight in a safe, sustainable way. It’s usually considered when lifestyle changes alone haven’t worked and your weight is affecting your health.

There are several types of weight loss medication available in the UK, including tablets and injections. 

The most effective treatments help regulate hunger and appetite. They can help you feel full for longer, reduce cravings, and naturally eat less.

How do weight loss medications work?

Many of the most effective weight loss medications, including Wegovy (semaglutide) and Mounjaro (tirzepatide), work by mimicking hormones that your body naturally produces after eating. These hormones help regulate appetite, blood sugar levels and how quickly food moves through your digestive system.

These medications strengthen the body’s natural signals of fullness, helping you feel satisfied sooner and for longer. This can make it easier to manage portion sizes and avoid habits like snacking or emotional eating.

They can also help support blood sugar balance, which can reduce cravings and improve energy levels – especially for people with insulin resistance or type 2 diabetes.

Wegovy is a weekly injection that mimics the hormone GLP-1 (glucagon-like peptide-1), helping to slow stomach emptying and curb appetite. 

Mounjaro is a newer treatment that acts on both GLP-1 and another hormone, GIP, offering dual action that may provide even greater support for appetite control and weight loss.

Alternatively, you can look at oral weight loss medications. Orlistat is a tablet that works differently from injectable weight loss medications. Instead of affecting appetite, it blocks the enzyme that helps digest fat, so your body absorbs less. This unabsorbed fat is passed out through your digestive system. Orlistat is taken with meals and is most effective when combined with a balanced diet and lifestyle changes.

All weight loss medications work best as part of a structured, long-term plan that includes healthy eating, regular activity and support from a specialist team.

Who is weight loss medication suitable for?

Weight loss medication may be an option if your current weight is affecting your health and other approaches haven’t worked.

You may be eligible for weight loss medication if:

• you have a BMI of 30 or higher
• you have a BMI of 27 or higher and a weight-related condition such as type 2 diabetes, high blood pressure, sleep apnoea, polycystic ovary syndrome (PCOS) or high cholesterol

At London Medical, we look at the full picture – your medical history, lifestyle and personal goals – before recommending any treatment. If weight loss medication is suitable, we’ll create a tailored plan to give you the best chance of success, supported by our expert team.

What results can I expect?

Everyone’s experience with weight loss medication is different. While some people may see noticeable results within a few weeks, for others it may take longer. Weight loss is usually gradual, which helps with long-term success and makes it easier to maintain over time.

The aim is not just to lose weight quickly, but to make lasting changes to your health and wellbeing that you can maintain. Many people find that when medication is combined with lifestyle changes and professional support, they feel more in control of their eating habits and better able to stick to healthy routines.

Our team will support you at every stage, helping you track your progress, adjust your plan if needed and stay motivated throughout your journey.

Is medication a long-term solution?

Weight loss medication works best as part of an ongoing plan. Some people stop once they’ve reached their target weight, while others may need longer-term support to maintain their progress.

Research shows that weight regain can happen after stopping medication, which is why continued support is key.

At London Medical, we’re committed to helping you achieve sustainable, healthy weight loss. Our multidisciplinary weight management team – including endocrinologists, dietitians and specialist nurses – will help you stay on track, whatever your goals.

Are there any side effects of weight loss medication?

Like all medications, weight loss treatments can cause side effects. These are usually mild and improve as your body adjusts to the medication.

The most common side effects can include:

• nausea
• diarrhoea or constipation
• headache
• indigestion
• tiredness

These effects often occur because weight loss medications change the way your digestive system works – slowing down how quickly food moves through your stomach and how your brain receives hunger and fullness signals. They tend to settle as your body adapts. Some people may notice symptoms only at the start or when the dose increases.

Less common effects can include dizziness, bloating or changes in taste. Serious side effects are rare but will be discussed with you fully before starting any treatment.

Throughout your plan, we’ll monitor your progress, ensure the medication is working safely and effectively, and help manage any symptoms to keep you feeling well.

How do I start weight loss medication?

If you’re finding it hard to lose weight and want to explore medical options, we’re here to help. 

At London Medical, you’ll receive access to:

• personalised assessments and blood tests
• tailored prescriptions for weight loss medications like Wegovy or Mounjaro
• ongoing support from an experienced, compassionate weight management team

You don’t need a GP referral, and appointments are available without delay. We’ll help you take control of your health with care and confidence.

Book a consultation with London Medical

If you’re considering weight loss medication and want expert guidance, we’re ready to support you. At London Medical, our team of specialists will work with you to create a safe, effective plan that prioritises your long-term health.

Contact us today to book your private consultation and begin your personalised weight management journey.