Several prescription medicines are licensed for weight management in the UK. They work in different ways and are not interchangeable. The right option depends on eligibility, medical history, treatment goals, side effects and ongoing clinical review.
Weight-management medicine can be appropriate when excess weight is affecting health and lifestyle measures alone have not produced a sufficient or durable response. The medicines available in the UK include weekly injections, daily injections, daily tablets and a medicine that reduces the absorption of dietary fat.
They are not cosmetic shortcuts and they are not interchangeable. A prescription should follow a proper clinical assessment, sit alongside nutrition and physical activity, and be reviewed for benefit, side effects and safety.
Heracles' current weight-management pathways include:
Wegovy tablets were authorised for UK weight management in June 2026 and are distinct from Rybelsus, a different semaglutide brand licensed for type 2 diabetes. The three Heracles options have different schedules, administration requirements and evidence. They are not direct dose substitutes, and an assessment may result in one of these pathways or no prescription.
The UK treatment landscape is changing quickly. This overview reflects current authorisations, but availability through an individual provider may lag behind a regulatory decision.
| Medicine | Active ingredient | Route and usual frequency | Main role in weight care |
|---|---|---|---|
| Mounjaro | Tirzepatide | Weekly injection | Reduces appetite and supports weight loss through GIP and GLP-1 receptor activity |
| Wegovy injection | Semaglutide | Weekly injection | Reduces appetite through GLP-1 receptor activity; used for weight loss and maintenance |
| Wegovy tablet | Semaglutide | Daily tablet | Oral GLP-1 option for weight loss and maintenance; administration instructions matter |
| Foundayo | Orforglipron | Daily tablet | Oral GLP-1 receptor agonist authorised for weight management; supply and provider availability must be confirmed |
| Orlistat | Orlistat | Capsule taken with relevant meals | Reduces absorption of some dietary fat rather than acting on appetite receptors |
| Saxenda and other liraglutide brands | Liraglutide | Daily injection | GLP-1 treatment with gradual dose escalation; service availability varies |
This table is not a prescribing recommendation. Exact indications, strengths, contraindications and administration instructions come from the current Summary of Product Characteristics and patient leaflet for the medicine supplied.
Mounjaro contains tirzepatide. It activates receptors for two naturally occurring gut hormones: glucose-dependent insulinotropic polypeptide, known as GIP, and glucagon-like peptide-1, known as GLP-1. Its effects include reduced food intake and improved glucose-dependent insulin responses.
Wegovy contains semaglutide, a GLP-1 receptor agonist. It acts on appetite regulation, helping many patients feel fuller, less hungry and less preoccupied by food.
Both medicines delay gastric emptying to some degree and commonly cause gastrointestinal symptoms, particularly during dose escalation. Neither medicine physically removes fat, and neither replaces the need for adequate nutrition, movement, sleep and long-term planning.
An oral medicine may appeal to someone who does not want injections, but a tablet is not automatically easier or safer.
Oral semaglutide for weight management has specific administration requirements, and its dose cannot be compared directly with the milligram strength of injected semaglutide. Orforglipron is a different molecule with its own product information. The prescriber must consider adherence, other medicines, gastrointestinal conditions, side effects and the person's daily routine.
Availability also matters. Regulatory authorisation does not guarantee that a product is immediately stocked, commissioned by the NHS or offered by Heracles. Check the current treatment page or ask during assessment which options are actually available.
Orlistat works in the gut by inhibiting enzymes that digest fat. This reduces absorption of some fat from food. It does not imitate GLP-1 and does not suppress appetite through the same pathway as semaglutide or tirzepatide.
Its practical success depends heavily on meal composition. High-fat meals increase the chance of oily stools, urgency and other gastrointestinal effects. A clinician or dietitian may also need to consider fat-soluble vitamins and other medicines.
Orlistat can be a reasonable option for some people who prefer a non-incretin treatment, cannot use another medicine or have different access considerations. It is not simply a weaker version of an injection; it is a different treatment with different trade-offs.
The product licences for Mounjaro and Wegovy include adults with:
Examples in current product information include high blood pressure, abnormal lipids, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes.
Meeting a numerical threshold does not guarantee a prescription. A clinician still needs to decide whether treatment is safe, likely to be beneficial and suitable for the individual. Conversely, BMI does not describe every aspect of risk, body composition or health. Waist measurement, ethnicity, blood pressure, glucose, symptoms, medicines and weight history can materially change the assessment.
NHS access criteria can be more restrictive than a medicine's marketing authorisation and may depend on commissioning rules and specialist-service pathways. Private prescribing still has to be clinically justified; paying privately does not bypass medical requirements.
A proper assessment should include more than height and weight. It may cover:
Tests are guided by history rather than ordered as a fixed commercial panel. HbA1c or glucose, lipids, liver tests, kidney function and other investigations may be appropriate. Men with relevant symptoms may also need assessment for sleep apnoea, erectile dysfunction, fertility concerns or testosterone deficiency, but weight alone is not a reason to order every hormone test.
Nausea, diarrhoea, vomiting, constipation and abdominal discomfort are common with incretin-based treatment. They are often more noticeable when treatment starts or the dose increases.
Persistent symptoms can cause dehydration, undernutrition and difficulty taking other medicines. A prescriber may delay escalation, reduce the dose or reconsider treatment instead of asking the patient to push through or increase the dose.
Severe, persistent abdominal pain needs urgent assessment because acute pancreatitis, although uncommon, can be serious. Gallbladder problems, severe allergic reactions and complications around anaesthesia also require appropriate advice. The MHRA advises patients to tell the surgical team if they use a GLP-1 medicine because delayed gastric emptying may affect aspiration risk.
Orlistat has a different side-effect pattern, dominated by bowel symptoms related to unabsorbed fat. Each medicine therefore needs its own side-effect and escalation guide rather than a generic disclaimer.
Treatment normally begins at a low starting dose and increases in stages. A higher dose is not a reward, a target or evidence that treatment is working better.
Dose decisions should consider:
Some patients remain on a lower tolerated dose. Others need a pause in escalation. There is no safe universal conversion when switching between brands, injections and tablets.
Clinical trials show average changes across selected groups receiving a defined dose, follow-up and lifestyle support. They do not predict what one patient will lose.
Response varies because of treatment adherence, tolerated dose, starting health, diabetes, sleep, activity, nutrition, medicines and biology. A responsible service monitors more than kilograms. Useful outcomes can include waist measurement, blood pressure, glucose, sleep, mobility, strength, treatment tolerance and quality of life.
Men should also be protected against avoidable loss of lean tissue. A larger appetite reduction can make it harder to consume adequate protein and total nutrition. Progressive resistance training, appropriate protein intake and attention to the rate of loss belong in the treatment plan from the beginning.
Obesity is commonly relapsing. Stopping medicine may allow appetite and weight-regulating biology to reassert themselves, and weight regain is common in treatment-withdrawal studies.
That does not mean every patient must use one medicine indefinitely. It means stopping should be planned. The review should cover benefit, side effects, affordability, other treatment options, nutrition, activity, sleep, behaviour and a monitoring plan.
Product information and NHS guidance include review points for deciding whether continued treatment is justified. Those rules are not identical across medicines or care settings.
The MHRA warns that GLP-1 medicines should only be used when prescribed by a healthcare professional and has not assessed them as a quick way to lose weight in people who do not meet medical requirements.
No. Escalation depends on the medicine, response and tolerability; significant symptoms or poor intake may justify delaying it.
A prescription-only medicine requires an appropriate prescriber assessment. A seller willing to bypass that process is a safety warning, not a convenience.
