Starting Wegovy: Your First Dose and First Month

Before Starting Wegovy

Wegovy contains semaglutide and is injected once a week. In the UK it is licensed for weight management in eligible adults alongside a reduced-calorie diet and increased physical activity. Eligibility is not decided by weight alone. The prescriber considers BMI, weight-related health conditions, previous treatment, current medicines and anything that could make Wegovy unsuitable or require closer monitoring.

Expect to provide an accurate medical history and a current list of prescribed, over-the-counter and herbal medicines. Depending on your circumstances, the assessment may also consider blood pressure, blood glucose or HbA1c, kidney and liver health, and possible weight-related conditions.

What should you tell the prescriber?

• Whether you use insulin or a sulfonylurea, as the risk of low blood sugar may increase when semaglutide is used with these medicines.
• Any history of pancreatitis, gallstones, serious digestive disease, diabetic eye disease, kidney problems or repeated dehydration.
• Whether you are pregnant, breastfeeding or planning pregnancy.
• Any planned operation or procedure involving general anaesthesia or deep sedation.
• Any other GLP-1 medicine or weight-management treatment you currently use.

Wegovy should not be used during pregnancy. Semaglutide should be stopped at least two months before a planned pregnancy. Speak to your prescriber rather than stopping or switching treatment without advice.

If treatment is suitable, you can view the current Wegovy injection options. Supply should follow a genuine clinical assessment from a regulated provider.

Your First Wegovy Dose: A Practical Checklist

The usual adult starting dose is 0.25 mg once a week for four weeks. Starting low helps reduce the likelihood and severity of digestive side effects while your body adjusts. The dose is normally increased gradually, but every change should follow the prescription and your prescriber's advice.

1. Check the medicine. Confirm the pharmacy label, pen strength and expiry date. The solution should appear clear and colourless.
2. Choose a weekly day. Pick a day you can remember. Wegovy can be used at any time of day, with or without food.
3. Read the supplied instructions. Learn how to attach a new needle, check the pen flow when required, select the prescribed dose and confirm that the dose counter returns to zero.
4. Choose the injection site. Wegovy can be injected into the abdomen, thigh or upper arm. Rotate the exact spot and avoid skin that is sore, bruised, hard or damaged.
5. Record the dose. Note the date, time, strength and any symptoms. This helps if a dose is missed or your prescriber reviews tolerability.
6. Remove the needle safely. Put it straight into a sharps bin and never share the pen or needle.

Our step-by-step explanation of how to inject Wegovy can help you understand the process, but the leaflet and instructions supplied with your own pen remain the main guide.

Do not use the clicks on the dose selector to estimate a different dose, and do not try to extract leftover medicine from the pen.

What to Expect in the First Week on Wegovy

There is no single first-week experience. Some people notice less hunger or earlier fullness, while others feel little difference after the first 0.25 mg dose. The starting dose is intended to introduce semaglutide gradually, so a quiet first week does not mean the treatment has failed.

Digestive symptoms can occur after the first injection. Nausea, diarrhoea, constipation, vomiting, stomach pain, indigestion and bloating are among the common effects. They may settle as your body adjusts, but timing and severity vary. Contact the prescribing team if symptoms persist, interfere with eating or drinking, or feel difficult to manage.

Avoid judging progress from a single weigh-in. Body weight can move up or down because of fluid, salt, digestion, hormones and the time of day. A consistent weekly routine gives a clearer picture than frequent reactive weighing.

Your First Month on Wegovy

For most people, the first four weeks remain at 0.25 mg once weekly. Do not move to 0.5 mg early because appetite remains strong or weight loss feels slow. The Wegovy dose schedule explains the later steps, while the prescribing team decides whether progression is appropriate for you.

Use the month to establish habits you can repeat: inject on the same day, eat manageable meals, drink regularly and keep a brief record of symptoms. Tell the prescriber if vomiting, diarrhoea or reduced intake makes it difficult to stay hydrated.

What if you miss your Wegovy dose?

If the missed dose was due no more than five days ago, use it as soon as possible. If more than five days have passed, skip it and take the next dose on your usual day. Do not take an extra dose to make up for one you missed. The missed Wegovy dose guide gives practical examples. Contact the prescribing team before restarting after several missed doses.

What Should You Eat and Drink When Starting Wegovy?

Start with portions that feel manageable and eat slowly. Very large, rich or fatty meals can be uncomfortable when semaglutide is slowing stomach emptying. Include protein regularly, add fibre gradually and choose fruit, vegetables and wholegrains according to what you tolerate. Our guide to what to eat on Wegovy explains how to build balanced meals without turning the first month into an extreme diet.

Drink regularly through the day. Vomiting and diarrhoea can cause dehydration and may worsen kidney problems. Seek advice if you cannot keep fluids down, are passing much less urine, feel faint or have another sign of dehydration. If you have heart or kidney disease, follow the fluid advice given by your own clinical team.

You do not need to force a very low calorie target. A moderate, sustainable deficit is more useful than severe restriction. The Wegovy weight loss calculator can provide an indicative starting point, but it does not replace personalised dietary or clinical advice.

Wegovy Side Effects and Warning Signs

Common digestive effects can often be managed with smaller meals, slower eating and regular fluids. Do not hide side effects because you want the next dose. The prescribing team needs an accurate account to decide whether treatment should continue, whether a dose increase should be delayed or whether another assessment is needed.

The detailed guide to managing Wegovy side effects covers nausea, diarrhoea, constipation, vomiting and reflux. Read the Patient Information Leaflet supplied with your medicine for the full list of risks and instructions.

When should you seek urgent medical help?

Get urgent medical help for severe, persistent stomach pain, particularly if it spreads to your back or is accompanied by nausea or vomiting. This can be a symptom of acute pancreatitis. Seek urgent advice for a serious allergic reaction, repeated vomiting, severe dehydration or another rapidly worsening symptom. Sudden loss of vision or rapidly worsening eyesight also needs urgent assessment.

If you use insulin or a sulfonylurea, ask how to recognise and manage low blood sugar. Do not rapidly reduce or stop insulin without clinical advice.

Storing and Handling Your Wegovy Pen

Before use, Wegovy should normally be kept in a refrigerator at 2°C to 8°C. Do not freeze it and do not use a pen that has been frozen. During use, the FlexTouch pen can be stored for six weeks below 30°C or in a refrigerator. Keep the cap on to protect the medicine from light.

Storage errors can affect whether the medicine is safe to use. The full Wegovy storage instructions explain fridge temperatures, travel and what to do after exposure to heat. Used needles belong in a sharps bin, while the pen and PenCycle arrangements are covered in our advice on how to dispose of Wegovy pens.

Tracking Progress and Reviewing Treatment

Record information that helps the prescriber judge safety and response: the dose, injection date, side effects, appetite, ability to eat and drink, and the overall weight trend. Weighing once a week under similar conditions is usually easier to interpret than reacting to daily changes.

A useful review covers more than kilograms lost. Tolerability, waist measurement, blood pressure, blood glucose where relevant, nutrition, strength and whether the routine is sustainable may all matter. The Wegovy weight loss timeline explains why results vary and why the first month cannot predict the complete response.

Contact the prescribing team if side effects continue, you are struggling to eat or drink, you want to change the injection day, or you have missed several doses. If you are taking Wegovy before surgery, tell the surgical or anaesthetic team. Do not stop it unless the clinical team tells you to do so.