The semaglutide dose for obesity — what the schedule actually means

Why the dose starts far below what does the heavy lifting

Most people reading about semaglutide for obesity focus on the 2.4mg figure. That's understandable, it's the dose used in the pivotal STEP 1 trial, which showed roughly 15% average body-weight reduction over 68 weeks. But treatment doesn't begin there. The first injection is 0.25mg, which is low enough that it has essentially no direct weight-loss effect. Its job is to let the gut, which is flooded with GLP-1 receptors, adapt to the medicine without triggering the nausea and vomiting that tend to hit hardest when the dose climbs too quickly.

After four weeks at 0.25mg, the prescriber moves the dose to 0.5mg, then 1mg, then 1.7mg, each stage lasting around a month, and you can read more about how each semaglutide dose works and what to expect at each stage if you want the detail behind those steps. The 2.4mg maintenance dose is where most of the clinical evidence sits. According to STEP 1, published in the New England Journal of Medicine, participants who reached and stayed at 2.4mg lost an average of about 15% of their body weight. That figure is from a 68-week trial in adults without diabetes. Real-world results vary.

If side effects become difficult at any step (which is most common in the first few weeks after a dose increase) the prescriber can hold the current dose for longer before advancing. Rushing the schedule doesn't produce faster results; it mostly produces more nausea. The people who do best tend to be the ones who go through each step steadily. That's not a comforting platitude; it reflects how the medicine interacts with GI motility.

The 7.2mg approval changes the ceiling, not the approach

In April 2026 the MHRA approved a dedicated single-dose 7.2mg semaglutide pen, one pre-set weekly injection, auto-dosing, with a built-in covered needle. This is the highest approved dose of semaglutide in the UK for weight management, and clinical data put average weight loss at around 20.7% over 72 weeks, closing much of the gap with tirzepatide at its highest dose. The MHRA's announcement makes clear that this pen is licensed specifically for adults with a BMI of 30 or above, not for the cardiovascular indication, and not for people below that threshold.

Crucially, the titration principle doesn't change. Treatment still starts at 0.25mg and climbs through the same graduated steps; 7.2mg is simply the new maximum rather than 2.4mg. For an overview of the full range of Wegovy doses and what each step involves, that detail is covered separately. The practical implication for someone starting treatment today: the early-dose experience is the same as it always was. What changes is the eventual ceiling for people who tolerate the escalation well and whose prescriber considers the higher dose appropriate, including those who progress to the semaglutide 2mg dose as an intermediate step before the higher end of the schedule.

Specific dose availability is confirmed at consultation, no pharmacy can guarantee which pen format or strength will be in stock at any given point.

Who the licensed dose schedule applies to, and what the prescriber weighs up

The UK licence for semaglutide in weight management covers adults with a BMI of 30 or above, or a BMI of 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK clinical guidance.

A prescriber doesn't just check the BMI box. They look at your medical history, any medicines you're already taking, and whether there are reasons the schedule would need to be adapted. Oral contraceptives are one example worth knowing about: NHS guidance notes there isn't the same evidence of reduced pill absorption with semaglutide as there is with tirzepatide, but the conversation about contraception is still part of a responsible consultation. For context on how the dose is used specifically in weight-loss treatment, that page looks at the eligibility picture in more detail.

People transferring from another provider, or requesting a dose increase, need to provide evidence of their current treatment. That's standard clinical practice, not bureaucracy. It stops dose escalation from becoming disconnected from what's actually happening to the patient.

Side effects by dose stage, and when to flag something

The most common side effects of semaglutide are gastrointestinal: nausea, loose stools, constipation, indigestion, reflux, and fatigue. These are listed on the NHS semaglutide medicines page and are generally most noticeable in the first few days after a dose increase, settling within one to two weeks for most people. At the 0.25mg starting dose they're usually mild. They tend to be more pronounced at 1mg and above.

Severe, persistent stomach pain (particularly if it radiates to the back, with or without vomiting) needs urgent medical attention. That's the pattern associated with acute pancreatitis, which the MHRA has highlighted as an infrequent but serious potential side effect of GLP-1 medicines. Don't wait to see if it passes. You can also report any suspected side effects through the MHRA Yellow Card scheme, which is open to patients as well as healthcare professionals.

Semaglutide is not recommended during pregnancy, while breastfeeding, or when trying to conceive. It isn't licensed for use in under-18s. These aren't caveats buried in the small print; they're the kind of detail a prescriber will ask about directly. If your situation changes after you start treatment, contact your prescriber before continuing.

If you'd like to explore whether semaglutide could be right for your situation, you can speak to our prescribers through a free consultation, reviewed the same day by a real clinician, not software. For a broader look at what treatment involves, our Wegovy overview covers the full picture, and if cost is a factor, Wegovy pricing sets out what to expect.