Wegovy comparison and guidance in the UK
This page helps you compare the main UK weight-management medicine options in a practical way: how they are usually taken, how NHS and private access differ, what side-effect patterns tend to look like, and which option may fit different situations better. It is designed to help you ask better questions before you start, switch, or review treatment.
The strongest comparison is not “which one is best in general?” but “which one fits your situation best right now?” The answer can change depending on how much weight loss you need, whether weekly or daily dosing suits you better, how sensitive you are to gastrointestinal side effects, how important NHS access is, whether you are planning pregnancy, and how much ongoing private cost matters.
For most visitors, the most useful order is: check whether you broadly meet eligibility, compare the medicine type, understand the side-effect trade-offs, then compare regulated providers only after that.
This table is designed for visitors, not prescribers. It strips the options back to the questions most people actually care about: what it is, how often it is taken, and what kind of person might realistically shortlist it.
| Medicine | Active ingredient | How it works in simple terms | How it is usually taken | Who may shortlist it |
|---|---|---|---|---|
| Wegovy Weekly injection | Semaglutide | GLP-1 receptor agonist that helps reduce appetite, increase fullness and slow stomach emptying. | Weekly, with dose escalation up to the usual 2.4 mg maintenance strength. | People who want a strong weekly GLP-1 option with extensive UK familiarity and a well-established prescribing pathway. |
| Mounjaro Weekly injection | Tirzepatide | Dual GIP and GLP-1 agonist, which acts on more than one appetite and metabolic signalling pathway. | Weekly, starting low and titrating upward in steps. | People prioritising the strongest average study outcomes where tirzepatide is clinically appropriate, affordable and tolerated. |
| Saxenda Daily injection | Liraglutide | Older-generation GLP-1 agonist for weight management. | Daily, titrated to 3 mg if tolerated. | People who cannot use or access a weekly injectable, or who prefer a daily adjustment rhythm. |
| Mysimba Oral | Naltrexone + bupropion | Acts through central appetite and craving pathways rather than the GLP-1 route. | Tablets, titrated upward over several weeks. | Selected adults where injectable treatment is not preferred or not suitable. |
| Orlistat Oral | Orlistat | Reduces dietary fat absorption in the gut rather than acting through appetite hormones. | Capsules taken with main meals that contain fat. | People looking for a lower-cost non-injectable route, accepting a more modest effect profile and dietary restrictions. |
Often feels like the benchmark weekly GLP-1 option: clear dose structure, strong weight-loss evidence, and broad recognition across UK provider comparison pages.
Usually enters the conversation when someone wants the strongest average outcome data, but it also brings separate questions around cost, access, contraception planning and tolerability.
Still matters because daily dosing can suit some people better, and because “older” does not automatically mean “wrong” if the medicine fits the person using it.
Usually matter most when injectables are not wanted, not tolerated, or not suitable. They are rarely chosen for the same reasons as Wegovy or Mounjaro.
Visitors often get misled by single headline numbers. A better way to compare is to ask four questions. Did the study include people with diabetes or not? How long were they followed? What dose did they actually reach? And was the medicine used alongside structured lifestyle support?
In real-world use, “best” usually means the medicine that gives you a strong enough response while still being tolerable, affordable and sustainable. For some people that will be Mounjaro, for some it will be Wegovy, and for others it will be a different route entirely.
Compare progress over 4 to 8 weeks, not one weigh-in after a salty meal, constipation, or a dose change.
People often compare two medicines while ignoring the fact that one was never titrated high enough or was stopped early for side effects.
A plateau is not automatic evidence that a medicine has failed. Intake drift, lower protein, and reduced activity are common reasons.
The option you can stay on safely and consistently often matters more than a dramatic first few weeks.
This is where many visitors get confused. A medicine can be licensed for private prescribing under broader criteria and still have a much narrower NHS route.
| Medicine | Typical private-prescribing position | NHS position visitors should understand | What that means in practice |
|---|---|---|---|
| Wegovy | Licensed for adults with BMI at least 30, or at least 27 with a weight-related comorbidity, subject to medical screening. | NICE weight-management guidance remains tied to specialist weight-management services, at least one weight-related comorbidity, and a maximum 2-year treatment period. | Many people who fit the private licence will still not get quick NHS access. |
| Mounjaro | Marketing authorisation also covers adults with obesity, or overweight with a weight-related comorbidity, subject to suitability review. | NICE NHS guidance is narrower, with an initial BMI threshold of at least 35 and at least one weight-related comorbidity. | Private eligibility and NHS access are not the same conversation. |
| Saxenda | Licensed for adults with BMI at least 30, or at least 27 with a weight-related comorbidity. | NHS use depends on local pathway design and service availability rather than a simple universal route. | Still relevant, but not usually the first comparison point for most visitors now. |
| Mysimba / Orlistat | Can be considered in selected adults under their own label criteria and contraindication checks. | NHS use varies by local practice and service model. | Often discussed when injectables are not suitable or not wanted. |
Most people do not stop because the medicine “does not work”. They stop because the side effects, cost, routine or support model stop feeling workable. The best comparison pages therefore need to talk about prevention, not just side-effect lists.
| Issue | What commonly helps | Which comparison it affects most |
|---|---|---|
| Nausea | Smaller meals, less dietary fat, slower eating, smaller sips, not forcing dose increases too quickly. | Usually central to Wegovy vs Mounjaro conversations. |
| Constipation | Regular fluids, soluble fibre, light movement, not letting intake fall too low. | Important across all GLP-1 style options. |
| Reflux and bloating | Smaller evening meal, less greasy food, staying upright after eating. | Can affect whether someone stays with a weekly injectable. |
| Adherence fatigue | Choosing a route that fits your real life rather than the one that only looks best on paper. | Often the reason daily Saxenda is ruled out by some people and preferred by others. |
| Dehydration risk | Electrolytes, early action on vomiting or diarrhoea, clinician advice if symptoms are prolonged. | Relevant to all GLP-1 style medicines. |
These are not prescribing rules. They are visitor shortcuts to help you think more clearly before a medical conversation.
These pages work best alongside this comparison guide because they answer the next questions people usually have after choosing a medicine shortlist.
These are the questions most likely to matter after reading the comparison table rather than before it.
Use this page to decide which medicine route deserves your attention first, then use the comparison pages to review regulated providers, listed fees and service structure more carefully.
Compare Wegovy providers