How Much Do Weight Loss Injections Cost — and What Do They Actually Do?

Medicines like Mounjaro and Wegovy work by acting on appetite-regulating pathways in the body. Wegovy contains semaglutide, a GLP-1 receptor agonist; Mounjaro contains tirzepatide, which acts on both GLP-1 and GIP receptors. Together, these effects are commonly reported to reduce appetite, lower food noise (the persistent mental preoccupation with eating), and slow the rate at which the stomach empties. For a fuller explanation of the mechanism, see our guide on how weight loss injections work in the body.

Do they actually help with weight loss?

Many people prescribed these medicines do experience meaningful changes in body weight over time, particularly when combined with changes to eating habits and physical activity. However, results vary between individuals — how quickly they start working, how much weight is lost, and how the body responds are all highly personal. These medicines are not a quick fix and are not suitable for everyone; suitability is a decision made by a prescriber based on your full medical history.

What about muscle mass, liver health, and cholesterol?

Questions about whether weight loss injections affect muscle mass, liver function, or cholesterol levels are common and reasonable. Rapid weight loss of any kind can affect body composition, which is why healthcare professionals often emphasise adequate protein intake and, where appropriate, resistance activity alongside treatment. Any specific concerns about how this medicine may be affecting your body — including your liver, cholesterol, immune system, or muscle — are worth raising directly with your prescriber or doctor, who can review your individual test results and history.

Do they give you energy or burn fat directly?

Some people report changes in energy levels during treatment, though experiences differ widely. These medicines work primarily through appetite and hormonal pathways rather than directly stimulating fat burning in the way exercise does. Changes in energy are commonly noted as part of the broader adjustment to reduced calorie intake and shifting metabolic patterns.

What about cost?

Cost is a practical concern for many people already on these medicines. Prices differ significantly by country, by whether treatment is accessed privately or through a publicly funded scheme, and by pen strength. GLP Trackr does not sell, supply, or source these medicines, and we do not quote prices — these change frequently and vary by location. For accurate, up-to-date pricing, speak with a registered pharmacy or your prescriber in your country. For more background on cost factors, see our page on weight loss injection pricing. If you are concerned about side effects during your treatment, our guide on whether slimming injections can make you feel unwell may also be useful.

Once you are prescribed a weight loss injection, consistency and self-awareness become two of the most important factors in your journey. GLP Trackr is built specifically for people already on Mounjaro or Wegovy, and its injection-site tracking feature is one of the most practical tools it offers.

Each time you inject, you can log the site — abdomen, thigh, or upper arm — and the app keeps a rotation history so it can suggest your next site automatically. Rotating sites correctly helps avoid tissue build-up and keeps each injection as comfortable as possible; the app makes that effortless rather than something you have to remember manually.

Beyond site rotation, GLP Trackr lets you log every dose and date so you always know exactly where you are in your schedule. If you experience side effects — nausea, fatigue, changes in energy, or anything else — the side-effect tracker lets you record them over time and spot patterns that are genuinely useful to bring to your next prescriber appointment.

For a broader overview of everything the app can support during your treatment, visit our weight loss injections hub.

A note on medical decisions: GLP Trackr records your journey and helps you spot patterns — it is not a substitute for your prescriber's guidance. Any questions about your dose, how the medicine is affecting your health, or whether to continue treatment should always be discussed with your healthcare professional. If any symptoms feel severe or persistent, contact them promptly.

Ready to track your injection sites, log every dose, and see your progress come together in one place? Download GLP Trackr on the App Store or Google Play — your first seven days are completely free.