What the Wegovy pen actually is
Weight-loss pens — the injections the press often calls "skinny jabs" — are pre-filled injector pens that deliver a GLP-1 receptor agonist as a small injection under the skin, into the abdomen, thigh or upper arm. The medicine reduces appetite and slows the emptying of the stomach, which is how it helps people eat less.[1] There is no vial, no syringe and no drawing-up: the pen arrives filled, and the needle is a short, fine, disposable one attached just before each injection.
Wegovy's specific hardware is Novo Nordisk's FlexTouch pre-filled pen, and its active ingredient is semaglutide, taken once weekly.[1] Semaglutide belongs to the wider category of weight loss injections used in the UK, and two naming points save a lot of confusion:
- Wegovy and Ozempic contain the same drug. Both are semaglutide, but Ozempic is licensed in the UK for type 2 diabetes at lower doses — not for weight loss. Using Ozempic for weight loss is off-label, and the MHRA advises that the licensed weight-loss route is Wegovy.[2]
- Wegovy and Mounjaro are different medicines. The Mounjaro pen contains tirzepatide, a dual GIP and GLP-1 receptor agonist made by Eli Lilly, with its own pen formats and dose ladder.[3] Both are UK-licensed for weight management, but they are not interchangeable.
What is in the box
Each Wegovy FlexTouch pen contains four once-weekly doses — roughly a month of treatment per pen — and each pack includes four disposable NovoFine Plus needles, one for each injection.[1] Each dose is injected under the skin of the abdomen, thigh or upper arm.[1]
The dose ladder: 0.25mg to 2.4mg over 16 weeks
Nobody starts Wegovy at full strength. The UK label sets out a 16-week escalation, moving up roughly every four weeks until the maintenance dose is reached:[1]
| Weeks | Once-weekly dose | Role |
|---|---|---|
| 1–4 | 0.25mg | Starting dose |
| 5–8 | 0.5mg | Second step |
| 9–12 | 1mg | Third step |
| 13–16 | 1.7mg | Fourth step |
| 17 onwards | 2.4mg | Standard maintenance dose |
The slow climb is not optional pacing. The label is explicit that the gradual step-up exists to reduce gastrointestinal side effects, which are most common while the dose is rising.[1] The steps move up roughly every four weeks until the 2.4mg maintenance dose is reached.[1] A prescriber may hold a dose for longer, or step it back, if side effects are troublesome — the ladder is a framework, not a countdown.
The 7.2mg update
The ladder above is the standard journey, but the ceiling moved in 2026. A higher 7.2mg once-weekly maximum maintenance dose was authorised in the UK in January 2026 — initially delivered as three separate 2.4mg injections on the same day — and on 14 April 2026 the MHRA approved a single-dose 7.2mg pen that delivers the full amount in one injection, for adults with obesity (a BMI of 30 or over).[4] Standard dosing still begins at 0.25mg weekly and steps up in the same gradual way.[4] Approval and everyday availability are not the same thing, so this page focuses on the 2.4mg FlexTouch pen the UK label describes.
The weekly routine
Wegovy is a once-a-week injection, given under the skin of the abdomen, thigh or upper arm.[1] That weekly rhythm is the single most practical fact about the pen: it is one small self-injection every seven days, not a daily commitment. Not every weight-loss pen works this way — Saxenda, the older liraglutide pen, is injected once every day rather than once a week.[5]
The mechanics — attaching the needle, checking the flow, choosing and rotating injection sites, and disposing of needles safely — are broadly the same across the weekly pens, and we walk through them step by step in Using your pen.
Storing the pen
Wegovy lives in the fridge. The label directs storage at 2–8°C, in the original carton, and the pen must never be frozen.[1] The label also permits a limited period at a higher temperature once a pen is in use; we deliberately do not quote a number of days here, because the patient information leaflet in your box is the instruction that counts, and your pharmacist can confirm it when the pen is dispensed.[1]
The Wegovy pen is a pre-filled, once-weekly semaglutide injector holding four doses. Treatment climbs a fixed ladder — 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg — over 16 weeks to reduce stomach-related side effects, and the pen is kept in the fridge at 2–8°C and never frozen.[1]
What the STEP trial showed
Wegovy's headline evidence is STEP 1, a 68-week, double-blind trial of 1,961 adults without diabetes, published in the New England Journal of Medicine on 10 February 2021. Mean weight change was −14.9% with semaglutide 2.4mg against −2.4% with placebo, and 86% of participants on semaglutide lost at least 5% of their body weight.[6]
One precision note, because this figure gets mangled online: the exact reported means were −14.85% and −2.41%, so the "about 15%" you see in coverage is a rounding of that.[6] A lower figure of 13.6% that some secondary sources quote for semaglutide belongs to a treatment-policy analysis of the separate oral tablet (the OASIS 4 trial), not the injectable pen studied in STEP 1 — the two sets of numbers are best kept apart.[10] Trial averages are also exactly that — averages, measured under trial conditions alongside diet and activity support; individual results differ, in both directions.
Side effects, briefly
The most frequently reported Wegovy side effects are gastrointestinal. In the pooled figures from the UK label, the "very common" reactions (affecting at least 1 in 10 people) are nausea (43.9%), diarrhoea (29.7%), vomiting (24.5%) and constipation (24.2%).[1] These are dose-related and tend to settle over weeks, which is exactly why the escalation ladder climbs slowly.[1] Our side effects guide covers the fuller picture — the common and rarer reactions, the label warnings and who needs extra caution.
Persistent vomiting or diarrhoea on Wegovy can cause dehydration, which in rare cases has led to worsening kidney function — keep fluids up and seek medical advice if you cannot keep fluids down.[1] Wegovy should not be used during pregnancy.[1] If you experience any suspected side effect from this or any medicine, report it through the MHRA Yellow Card scheme[8] and speak to your GP or pharmacist.
UK status: licensed, and on the NHS — narrowly
Wegovy is fully licensed in the UK. The label covers adults with a BMI of 30 or more, or a BMI of 27 to under 30 alongside at least one weight-related health problem, and it also covers adolescents aged 12 and over with obesity and a body weight above 60kg.[1]
A licence, though, is only the first of two gates to NHS funding: a medicine must be MHRA-licensed and then recommended by NICE before the NHS routinely pays for it.[7] For Wegovy, NICE's recommendation (TA875) is deliberately narrow: treatment within a specialist weight-management service, for a maximum of 2 years, and stopped if less than 5% weight loss has been achieved after 6 months on the maintenance dose.[9] In practice that makes NHS access much tighter than the licence itself.
Away from the NHS, Wegovy can also be prescribed privately. The route does not change what the medicine is: a qualified prescriber still assesses whether you meet the licensed criteria and whether it is appropriate for you before it is supplied against that prescription, and it is dispensed by a GPhC-registered pharmacy. Nothing about a private consultation makes Wegovy suitable for someone outside the licence — the MHRA is clear that it has not assessed the safety or effectiveness of these medicines outside their licensed use, for example in people who are not living with overweight or obesity.[2]
Frequently asked questions
How many doses are in a Wegovy pen?
Four. Each FlexTouch pen holds four once-weekly doses — about a month of treatment — and each pack includes four disposable NovoFine Plus needles, one per injection.[1]
How does the Wegovy pen work?
The pen injects semaglutide, a GLP-1 receptor agonist, under the skin of the abdomen, thigh or upper arm once a week. The medicine reduces appetite and slows stomach emptying, which helps people eat less.[1] The pen is pre-filled, so there is nothing to measure or draw up.
Is the Wegovy pen available on the NHS?
Yes, but through a narrow gate. NICE (TA875) recommends it only within a specialist weight-management service, for a maximum of 2 years, with treatment stopped if less than 5% weight loss is achieved after 6 months on the maintenance dose.[9]
Does the Wegovy pen need to be kept in the fridge?
Yes — at 2–8°C, in the original carton, and never frozen. Once a pen is in use the label permits a limited spell at higher temperature; the exact window is in the patient information leaflet in the box, which is the instruction to follow.[1]
What is the strongest Wegovy dose?
Is Wegovy the same as Ozempic?
Same drug, different products. Both contain semaglutide, but Ozempic's UK licence is for type 2 diabetes at lower doses — not weight loss — so weight-loss use of Ozempic is off-label. The MHRA advises that the licensed weight-loss route is Wegovy.[2]
References
- electronic Medicines Compendium (emc). "Wegovy FlexTouch — Summary of Product Characteristics" (product 13803). medicines.org.uk
- MHRA / GOV.UK. "MHRA updates guidance for semaglutide prescribers and patients". gov.uk
- electronic Medicines Compendium (emc). "Mounjaro KwikPen — Summary of Product Characteristics" (product 15481). medicines.org.uk
- MHRA / GOV.UK. "Single-dose 7.2mg semaglutide (Wegovy) pen approved to treat adult patients with obesity", 14 April 2026. gov.uk
- electronic Medicines Compendium (emc). "Saxenda 6mg/mL solution for injection in pre-filled pen — Summary of Product Characteristics" (product 2313). medicines.org.uk
- Wilding JPH et al. "Once-Weekly Semaglutide in Adults with Overweight or Obesity" (STEP 1). New England Journal of Medicine, 10 February 2021. nejm.org
- MHRA / GOV.UK. "First GLP-1 tablet for weight loss approved in the UK", 11 June 2026. gov.uk
- MHRA. Yellow Card scheme — report a suspected side effect. yellowcard.mhra.gov.uk
- NICE. "Semaglutide for managing overweight and obesity" — Technology Appraisal TA875, Recommendations. nice.org.uk
- PR Newswire / Novo Nordisk. "FDA approves Novo Nordisk's Wegovy® pill, the first and only oral GLP-1 for weight loss in adults" (OASIS 4 results, including the 13.6% treatment-policy figure for the oral tablet). prnewswire.com