Wegovy size: understanding the pens, doses and how they change

You've just opened a box with a different number on it, here's what that means

Picture the situation: the pen in this week's delivery is a different colour band from last month's, or the number printed on the label has jumped. It is easy to feel a flicker of anxiety, did the pharmacy send the wrong thing? Is this too much? The short answer is that Wegovy is designed to be used in exactly this way. The dose is meant to change over time, and each step up is part of a planned titration schedule that your prescriber sets.

Semaglutide, the medicine inside every Wegovy pen, works the same way at every strength. It activates GLP-1 receptors in the brain and gut, reducing appetite and slowing how quickly food leaves the stomach. What changes with a higher-numbered pen is simply how much of that compound you receive each week, and if you are curious about how semaglutide sizing works across the different strengths, that page walks through each dose in plain terms. The semaglutide overview covers the mechanism in more detail if you want to understand what is happening at a biological level.

In practical terms, the UK licensed titration pathway runs: 0.25 mg for the first four weeks, then 0.5 mg, then 1.0 mg, then 1.7 mg, then 2.4 mg as the standard maintenance dose, each step approximately four weeks apart, per your prescriber's direction. The NHS medicines guidance on semaglutide describes this schedule as a tolerability measure; the lower doses let your digestive system adapt before the full therapeutic level is reached. Your prescriber decides the pace, and they may slow it down if side effects are troublesome at a particular step.

The 7.2 mg pen: what changed in April 2026 and what it means for the Wegovy range

Until early 2026, 2.4 mg was the ceiling for Wegovy. That changed when the MHRA approved a higher maintenance dose, and then on 14 April 2026 announced approval of a dedicated single-dose 7.2 mg Wegovy pen, one pre-set weekly injection with an auto-dosing mechanism and a built-in covered needle that locks after use. This approval is for adults with obesity and a BMI of 30 or above; it is not indicated for the lower BMI threshold or for the cardiovascular risk indication.

The clinical data behind the 7.2 mg dose reported an average weight loss of around 20.7% over 72 weeks, which narrows the gap with tirzepatide considerably. That figure comes from trials, not from a guarantee about any individual's outcome, results vary depending on adherence, diet, activity and a person's physiology. The Wegovy treatment page sets out the full evidence picture.

One practical point worth knowing: the 7.2 mg pen uses a different design from the 0.25–2.4 mg pens in the current range. If your prescriber and you decide to explore this higher dose in future, it will be a different physical device. Never attempt to combine multiple lower-dose pens to approximate the higher dose; that is not how the dosing system works and it is not clinically safe.

Availability of specific pen formats is confirmed at consultation, supply and clinical suitability both factor in. If you want to know what size you could be eligible for, our Wegovy access page explains the process step by step.

Why the pen you're on now might not be the pen you stay on

A question our prescribers hear often is some version of: "I've been on 1.0 mg for two months, is that the dose I'm stuck on?" The answer is no. Titration is a live process. If you are tolerating the current strength well and your progress warrants it, the next step up is the natural clinical decision. Equally, if a dose increase causes persistent side effects (nausea that does not settle, stomach pain, significant vomiting) a prescriber may hold you at the current strength for longer or revisit the timeline. This is not failure; it is the medicine being tailored to you.

Side effects across the Wegovy range are largely gastrointestinal: nausea, loose stools, constipation, indigestion and reflux are the most commonly reported, and they tend to be most noticeable in the first one to two weeks at a new dose before easing. Staying hydrated, eating smaller portions and keeping fatty or very rich foods to a minimum can help. The NHS semaglutide medicines page lists side effects in full and explains when to seek medical advice urgently, including for severe abdominal pain, which should always be assessed promptly.

The Wegovy sizes chart shows the full pen range with the expected titration timeline, which can be a useful reference alongside your prescriber's guidance. For a look at how the pen dimensions themselves compare across the range, the pack size detail page covers what arrives in the box at each step.

Cost is a reasonable thing to factor in when thinking about long-term treatment. Private Wegovy pricing has shifted since Eli Lilly's UK list price changes in late 2025 set a new market benchmark; if cost context is helpful, the weight-loss treatment overview includes an honest look at what private treatment involves financially.