Weight-Management Medicines in the UK

Compare weight-management medicines, then explore doctor-led Heracles care with monthly check-ins, dose reviews and ongoing support.

Table of contents

Weight-management medicines can help reduce appetite or change how dietary fat is absorbed. The right option depends on your health, daily routine and how you respond to treatment.

Heracles brings doctor-led weight care together with monthly check-ins, dose reviews and ongoing support. Our team includes Dr Ian Gallen, Consultant Endocrinologist, with expertise in diabetes, hormones and metabolic health.

At a glance

  • Mounjaro and Wegovy work differently and have different dosing instructions.
  • Your medical history, other medicines and treatment tolerance guide the choice.
  • Use only a legitimate prescription and follow the instructions for your exact medicine.

Which weight-management options does Heracles assess?

Heracles' current weight-management pathways include:

  • Wegovy tablets: semaglutide taken once daily;
  • Wegovy injection: semaglutide injected once weekly; and
  • Mounjaro: tirzepatide injected once weekly.

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.

Which weight-management medicines are available?

Available options differ by medicine and provider. The table below summarises the main routes and schedules.

MedicineActive ingredientRoute and usual frequencyMain role in weight care
MounjaroTirzepatideWeekly injectionReduces appetite and supports weight loss through GIP and GLP-1 receptor activity
Wegovy injectionSemaglutideWeekly injectionReduces appetite through GLP-1 receptor activity; used for weight loss and maintenance
Wegovy tabletSemaglutideDaily tabletOral GLP-1 option for weight loss and maintenance; administration instructions matter
FoundayoOrforglipronDaily tabletOral GLP-1 receptor agonist authorised for weight management; supply and provider availability must be confirmed
OrlistatOrlistatCapsule taken with relevant mealsReduces absorption of some dietary fat rather than acting on appetite receptors
Saxenda and other liraglutide brandsLiraglutideDaily injectionGLP-1 treatment with gradual dose escalation; service availability varies

Follow the current patient leaflet and prescribing instructions for the medicine supplied.

How do Mounjaro and Wegovy work?

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.

What is different about tablets?

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.

Where does orlistat fit?

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.

Who may be considered for prescription treatment?

The product licences for Mounjaro and Wegovy include adults with:

  • a BMI of 30 kg/m² or more; or
  • a BMI from 27 kg/m² to below 30 kg/m² with at least one weight-related health condition.

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.

What should the assessment cover?

A proper assessment should include more than height and weight. It may cover:

  • weight history, previous treatment and patterns of regain;
  • waist measurement, blood pressure and pulse;
  • symptoms or diagnoses linked to diabetes, sleep apnoea, cardiovascular disease or fatty liver disease;
  • current prescriptions, supplements and recreational drugs;
  • gastrointestinal, pancreatic and gallbladder history;
  • kidney and liver health where relevant;
  • eating-disorder symptoms and psychological wellbeing;
  • upcoming surgery or procedures involving anaesthesia or deep sedation;
  • ability to eat enough protein, fibre and micronutrients during appetite suppression;
  • treatment goals, preferences, cost and the ability to attend reviews.

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.

What side effects should patients understand?

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.

How are doses chosen?

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:

  • appetite and eating pattern;
  • rate of weight change;
  • gastrointestinal symptoms;
  • hydration and nutritional intake;
  • blood glucose and diabetes treatment where relevant;
  • other adverse effects;
  • the person's goals and clinical response.

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.

What results are realistic?

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.

How long is treatment used?

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.

How to use weight-management medicine safely

  • Use only medication prescribed for you.
  • Follow the instructions for the exact product and device supplied.
  • Do not combine, split, extract or improvise doses.
  • Do not switch brand or route without the prescriber.
  • Report severe or persistent side effects early.
  • Tell clinicians about treatment before surgery or deep sedation.
  • Attend monitoring and provide honest information about symptoms and intake.
  • Avoid sellers who offer prescription medicine without an adequate assessment.

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.

Choose your next step with Heracles

Your assessment gives the clinical team the information needed to recommend a suitable pathway. Ongoing reviews cover progress, side effects and dose decisions, with nutrition and activity remaining part of the plan.

Explore Heracles weight-loss care and the treatment options currently available.

More frequently asked questions

Do I have to reach the maximum dose?

No. Escalation depends on the medicine, response and tolerability; significant symptoms or poor intake may justify delaying it.

Can I buy GLP-1 medicine without a consultation?

A prescription-only medicine requires an appropriate prescriber assessment. A seller willing to bypass that process is a safety warning, not a convenience.

Find the weight-management pathway that fits your health and routine. Start your Heracles assessment.