What Is Wegovy? How It Works, Who It Is For, and How Dosing Works

• Explains what Wegovy is and what it is licensed to treat in the UK
• Sets out who is eligible and who it is not suitable for
• Explains how Wegovy dosing works and why it starts low and builds
• Covers the maximum dose question, side effects by stage and review points

Wegovy is one of the most searched medicines in the country and one of the least well explained. People arrive at a consultation having heard the name everywhere and knowing very little about what it actually is, and the part that causes most confusion is the dosing.

That confusion has consequences. People assume a higher dose means a stronger result, that the aim is to reach the top of the ladder, and that a difficult week means the medicine is not working for them. None of those is right, and each one makes treatment harder than it needs to be.

This page answers the questions people actually type. It explains what Wegovy is, what it is used for, who can have it in the UK, and how its dosing works. It does not publish a dose schedule, because the schedule for any individual is set by their prescriber against the approved product information. What it does explain is the reasoning behind it, which is the part that makes the difference.

Key things to know

• Wegovy is a prescription only medicine. The MHRA is clear that medicines in this class can only be prescribed by a healthcare professional.
• It is given as a once weekly injection under the skin, using a pre-filled pen.
• It works mainly by reducing appetite, not by blocking fat absorption or raising metabolism.
• Doses start low and increase in steps for tolerability, not because low doses do nothing.
• The aim is to find a dose that provides a useful response and is well tolerated, in line with the approved dosing instructions and your prescriber's advice. This may not always mean reaching the maximum licensed dose.

What is Wegovy?

Wegovy is a prescription-only medicine containing semaglutide, used for weight management alongside a reduced-calorie diet and increased physical activity. In the UK, it is available as a once-weekly injection and, following approval of the oral formulation in June 2026, as a tablet taken daily. The formulations have different dosing instructions and should not be treated as interchangeable.

The MHRA describes medicines in this class as helping people feel fuller by mimicking a natural hormone released after eating. That single sentence explains both what Wegovy does and why appetite is the thing that changes. Wegovy contains the active ingredient semaglutide, a semaglutide injection designed to reduce excess weight and support weight loss medication programs. Wegovy may be prescribed following an appropriate clinical assessment. NHS prescribing and eligibility criteria depend on the applicable NICE guidance and local service arrangements. Treatment should be combined with a reduced-calorie diet and increased physical activity.

Wegovy works by gradually increasing dose strengths over several weeks to reach a maintenance dose that optimizes weight loss while minimizing side effects. It is important not to miss a dose or take a dose early, and if you miss a dose, do not double dose; instead, follow guidance on when to take the next dose or next scheduled dose to maintain steady blood sugar levels and avoid low blood sugar risks.

People with kidney problems or cardiovascular disease should discuss their medical history with their prescriber before starting Wegovy. Suitability depends on the individual's condition and the relevant product information. Alcohol is not universally prohibited, but it may worsen gastrointestinal symptoms or contribute to dehydration, particularly if vomiting occurs.

What is the Wegovy injection?

The Wegovy injection is given once a week into the fatty tissue under the skin using a pre-filled pen. The usual injection sites are the abdomen, thigh or upper arm. Follow the instructions supplied with your pen and rotate injection sites as advised.

It is not an intravenous injection, it is not given by a nurse, and it does not require any equipment beyond the pen and a sharps bin. Most people give it themselves at home after being shown how.

The weekly format is one of the practical differences between the medicines licensed for weight management here, so it is worth seeing how it sits against the alternatives. You can compare licensed weight loss treatments in the UK and what each one involves.

What is Wegovy made of?

The active substance is a peptide, which is a short chain of amino acids manufactured to closely resemble a hormone your own gut produces. It is modified so that it lasts far longer in the body than the natural hormone, which survives only minutes. That modification is what allows one injection to cover a whole week.

The inactive ingredients depend on the specific Wegovy formulation and product. Check the patient information leaflet supplied with your medicine for the complete ingredient list, especially if you have a known allergy.

The approved patient information leaflet supplied with your pen lists the full ingredients, which matters if you have known allergies.

How does Wegovy work?

Three effects, working together rather than separately.

It acts on appetite signalling in the brain, which reduces hunger and the pull towards food between meals. It slows how quickly the stomach empties, so a meal produces fullness that lasts longer. And it increases insulin release in response to eating while reducing glucagon, which is why this class was developed for type 2 diabetes before its effect on weight was licensed separately.

For many people, Wegovy reduces hunger and helps them feel satisfied with smaller amounts of food. This can make it easier to maintain changes in eating habits, although the response varies between individuals.

What is Wegovy used for?

Wegovy is used alongside a reduced-calorie diet and increased physical activity. NHS eligibility and prescribing arrangements depend on the applicable NICE recommendations and local service pathways, which may be more restrictive than the medicine's UK marketing authorisation.

One question comes up constantly and deserves a direct answer. The same active substance can hold separate licences under different product names, one for weight management and one for type 2 diabetes. They are different products with different licensed uses, different dose ranges and different approved patient information, which is why they are not interchangeable even where the active substance is shared.

Who can take Wegovy in the UK?

Eligibility is based on BMI and on whether you have a weight related health condition, and it is settled by clinical assessment rather than by a number you can look up.

• Under the UK marketing authorisation for injectable Wegovy, adults may be eligible for weight management treatment if their initial BMI is 30 or above, or if their BMI is 27 to below 30 and they have at least one weight-related health condition. NHS prescribing criteria may be more restrictive and can include additional requirements relating to specialist services and ethnicity. A prescriber must assess individual suitability.
• A lower BMI threshold applies where at least one weight related condition is present, such as high blood pressure, raised cholesterol, obstructive sleep apnoea or type 2 diabetes.
• Ethnicity is taken into account, because BMI does not carry the same risk at the same number across all populations.
• You must be an adult, and the assessment covers your full medical history rather than your BMI alone.

Criteria differ between the individual medicines licensed for weight management, so a threshold you have read about elsewhere may not be the one that applies to Wegovy or to you. Treatment suitability depends on an individual clinical assessment.

Who Wegovy is not suitable for

A legitimate assessment looks for reasons not to prescribe as carefully as reasons to.

Wegovy should not be used during pregnancy, and semaglutide should be stopped at least two months before a planned pregnancy. A known allergy to semaglutide or an ingredient in the product is a contraindication. A history of pancreatitis, severe gastrointestinal problems and other relevant medical conditions require individual assessment and may affect whether treatment is appropriate.

Other medicines matter too. If you take insulin or a sulfonylurea for diabetes, combining them with this class raises the risk of low blood glucose and needs careful management rather than simple addition.

How Wegovy dosing works

Wegovy starts at a low dose and increases in planned steps over a period of months. This is not a commercial structure and it is not caution for its own sake. It exists for one specific reason, and understanding it changes how treatment feels. The dose increase is carefully managed to reduce the risk of severe stomach pain and other gastrointestinal side effects. Each dose is administered using the Wegovy pen, which includes a pen cap to keep the needle sterile until use.

Patients are advised to inject Wegovy in the same body area but rotate to the exact same spot only after a suitable interval to minimize skin irritation. Knowing how many doses are left before the expiration date is important to ensure the full dose is used effectively. If a dose is missed, patients should not double up but follow guidance on whether to skip the missed dose or take it the same day, depending on timing. Additionally, patients should avoid drinking alcohol while on Wegovy to prevent adverse effects and consult healthcare professionals before combining it with other weight loss medications or treatments. The current dose and timing of the last injection are crucial details to track for safe and effective treatment.

Wegovy's dose-escalation schedule is designed primarily to improve tolerability and reduce gastrointestinal side effects. Dose changes should follow the approved product information and the prescriber's advice. Cardiovascular risk management is a separate consideration that depends on the patient's clinical circumstances.

What is the Wegovy starting dose for?

The starting dose is not chosen to produce weight loss. It is chosen to let your gut meet the medicine at a level it can handle.

The most common side effects of this class are gastrointestinal, and they are at their most pronounced when the body first encounters the medicine or encounters more of it. Beginning at a higher dose would not produce faster results. It would produce nausea severe enough that most people would stop.

So a small weight change in the first weeks is expected rather than disappointing. The early part of the ladder is doing a different job.

How does Wegovy dose escalation work?

Each step is a small increase, followed by a settling period before the next one. The steps and the intervals between them are set in the approved product information, which is the document your prescriber works from, and they apply to Wegovy specifically rather than to weight loss medicines generally.

Two things are worth knowing in advance. The ladder is a plan rather than a contract, so a prescriber can hold you at a step for longer or keep you at a lower dose indefinitely if that is where you are doing well. And the interval at each step is a minimum, not a deadline. Increasing the dose too quickly or before symptoms have settled may make gastrointestinal side effects harder to manage. Follow the prescribed schedule and contact your prescriber if symptoms persist or become difficult to tolerate.

The same principle applies to oral GLP-1 treatment for people who will not inject, which also begins low and builds. The format changes; the reasoning behind the ladder does not.

How long do you stay on each Wegovy dose?

Long enough for side effects to settle and for the step to be assessed, which is a period of weeks rather than days at each level. The specific interval is set in the product information and your prescriber will tell you what applies to you.

If a step is proving difficult, that is a clinical conversation rather than something to endure quietly. Holding at the current step, or stepping back and rebuilding more slowly, are both ordinary decisions.

What is the maximum Wegovy dose?

The maximum licensed dose depends on the Wegovy formulation and the applicable product information. For the injectable formulation, the UK product information updated in September 2026 includes a 7.2 mg once-weekly option for certain adults with obesity when needed. This is not a dose that everyone should aim to reach. Your prescriber will determine the appropriate dose and whether escalation is suitable.

What Wegovy dose should I take?

The dose that gives you a useful result with side effects you can live with. That is genuinely individual, which is why no article can tell you your dose.

Your prescriber will determine the appropriate treatment and the appropriate dose based on how you are responding, what side effects you are having, your other medicines and your other conditions. Results vary between individuals, and two people at the same dose can have quite different experiences.

Adjusting your own dose, or using any medicine outside the terms of its licence, is not something to attempt. The answer is no, and the reason is that the escalation intervals and the maximum exist because of safety data.

Wegovy side effects by dose stage

Side effects in this class track dose changes more closely than dose level. Somebody stable at a higher step often has an easier time of it than somebody who moved up three days ago.

The MHRA notes that gastrointestinal side effects may affect more than one in ten patients, with nausea, vomiting and diarrhoea among the most common. It also asks prescribers to discuss less common but serious risks including pancreatitis and gall bladder disorders, and notes that inflammation of the pancreas has been reported with medicines in this class, including rare reports with serious or fatal outcomes.

Managing a difficult step

Contact your prescriber if side effects are persistent or difficult to manage. Do not push through severe symptoms. Severe or persistent abdominal pain, particularly with vomiting, needs urgent medical assessment.

Practical measures help alongside any clinical adjustment: smaller meals, eating more slowly, easing off very rich or very fatty food during the adaptation days, and keeping fluids up if you have been unwell. Some people find that gastrointestinal side effects ease as their body adjusts to treatment, although symptoms can persist or return after a dose increase. The experience varies between individuals.

Missed dose

If you miss a dose of injectable Wegovy, follow the instructions in the patient information leaflet supplied with your pen. The approved instructions specify what to do according to how much time has passed since the missed dose. Do not take a double dose to make up for a missed one. If you have missed multiple doses or are unsure how to restart treatment, contact your prescriber.

How Wegovy treatment is reviewed

The UK product information advises that, if an adult has not lost at least 5% of their initial body weight after six months of treatment, the prescriber should decide whether continuing is appropriate, taking the individual's benefits and risks into account. NICE's NHS recommendations and the product licence should be distinguished when explaining how this review applies in practice.

What happens if you stop Wegovy

Appetite generally returns and weight regain is common. That is not a flaw in the medicine and it is not a personal failure. It is what happens when treatment for a long term condition is withdrawn.

NICE addresses this directly, advising that support to help maintain weight loss should be offered to people who are stopping weight management medicines, and recognising that overweight and obesity can be a long term health issue and that relapses are normal.

The practical implication is that the plan for stopping matters as much as the plan for starting and should be discussed before you begin. Ongoing weight loss support alongside treatment is the part of the pathway most commonly skipped.

Getting Wegovy safely in the UK

Wegovy is prescription only, so any legitimate supply begins with an assessment by a healthcare professional. The MHRA is explicit that medicines in this class should not be bought from unregulated sellers such as beauty salons or social media, or from anywhere without a prior consultation.

A legitimate service should arrange an appropriate clinical assessment, review relevant medical history and other medicines, and ensure that prescribing and dispensing are carried out by appropriately qualified professionals and registered providers. Patients should receive the relevant product information and a clear route to follow up with their prescriber if problems arise.

Suspected side effects can be reported through the MHRA Yellow Card scheme. You do not need to be certain the medicine caused the problem to report it.

Medical Disclaimer

This article is general information about prescription only medicine and is not medical advice. It contains no dosing instructions and no dose escalation schedule, and it is not a substitute for a consultation with a qualified healthcare professional. Wegovy should only be used under the supervision of an appropriately qualified prescriber and in line with the approved patient information leaflet supplied with your medicine.

Treatment suitability depends on an individual clinical assessment, and results vary between individuals. Seek urgent medical attention for severe or persistent abdominal pain, repeated vomiting, sudden changes in vision, or signs of an allergic reaction such as swelling of the face, lips or throat or difficulty breathing. Suspected side effects can be reported through the MHRA Yellow Card scheme.