Wegovy pen sizes: which formats and doses are available in the UK?

What are the different Wegovy pen sizes and what does each one contain?

The word "size" in this context refers to dose strength rather than the physical dimensions of the device. Each Wegovy pen is pre-filled with a fixed amount of semaglutide: 0.25mg, 0.5mg, 1.0mg, 1.7mg or 2.4mg. Standard pens contain four pre-set weekly doses, so one pen covers a full four-week supply at that strength. You don't refill them or draw up a dose manually, each injection is already measured, and the pen advances to the next dose window automatically after use.

The physical pen itself is broadly similar across the standard range: a pre-filled auto-injector made by Novo Nordisk with a small hidden needle. Our page on the Wegovy pen device covers the injection mechanism in more detail if that's what you're researching. What changes between pens is purely the concentration of semaglutide delivered per dose.

Storage follows the same rule for all standard Wegovy pens: refrigerate between 2°C and 8°C. The exact room-temperature window if a pen is temporarily out of the fridge is set out in the Patient Information Leaflet, always check that, rather than relying on a general figure online.

What is the 7.2mg Wegovy pen and how does it differ from the earlier formats?

On 14 April 2026, the MHRA approved a dedicated single-dose 7.2mg Wegovy pen, making the UK the first country to offer this higher maintenance dose in a single weekly device. Before that approval, patients prescribed 7.2mg were using three standard 2.4mg pens in a week, effective but logistically cumbersome.

The new pen is a distinct device. It has an auto-dosing mechanism, a built-in covered needle that activates on injection, and locks after a single use. One pen equals one weekly injection at 7.2mg. It is approved specifically for adults with obesity defined as a BMI of 30 or above; it is not licensed for the lower BMI threshold or for the separate cardiovascular indication. The full Wegovy overview covers the eligibility criteria across the range.

Clinical trial data reported around 20.7% average weight loss over 72 weeks at 7.2mg, which brings results closer to those seen with tirzepatide at higher doses. Whether 7.2mg is clinically appropriate for a particular person is a prescriber's call, not something to self-select. If you're already on 2.4mg and wondering whether the higher dose is relevant to you, that conversation belongs with whoever is managing your treatment.

Do the needle sizes differ between Wegovy pens?

The needle gauge is set by the pen, not chosen separately for the standard Wegovy range. If you want to understand exactly what gauge and length comes with each pen, our dedicated page on Wegovy needle sizes goes through the specifics, including how the dimensions vary across the dose range. For the 7.2mg pen, the covered built-in needle is part of the fixed device design rather than something you attach beforehand.

One thing worth knowing: Wegovy needles should be discarded safely after each injection. A 1-litre sharps container is the standard way to do that at home, and NHS guidance recommends collecting used needles this way rather than putting them in general household waste. A lot of people sort this out before their first pen arrives rather than after, it takes about two minutes to order and sits quietly under the bathroom sink until you need it.

If you're comparing needle specifications across different semaglutide devices, semaglutide needle sizes across the range are covered separately, as the gauge can differ by product and format.

Can you swap between pen sizes yourself, and what affects which pen you'll be on?

No. The titration schedule (which pen you use and when you move to the next strength) is governed by your prescriber. The standard licensed pathway runs from 0.25mg through to 2.4mg in roughly four-weekly steps, with 7.2mg available for those who need and qualify for it. Skipping steps or holding at a lower dose for longer than planned are both decisions for a clinician, based on how you're tolerating the medicine and how your weight is responding.

The NHS semaglutide medicines page sets out the general dose information patients need, and the MHRA-approved Patient Information Leaflet inside your box covers the schedule in full. Neither source will tell you to change your own dose; they both point back to your healthcare team.

If you're transferring from another provider and want to continue at a current dose, a prescriber will ask for evidence of your existing treatment before authorising any repeat. That's standard clinical practice, not a hurdle. Cost context for the treatment overall, including what's typically included in a private prescription, is on our Wegovy cost page. And if you're still weighing up whether Wegovy or another treatment is right for your situation, our weight-loss treatment overview sets out the options clearly.

If this has prompted questions specific to your health history, our prescribers are the right people to ask. You can start a free consultation and a GPhC-registered Independent Prescriber will review your details the same day.