Wegovy 1 mg: the evidence behind this titration step

Where the STEP trial evidence places 1 mg in the schedule

The STEP programme, which generated the evidence base for Wegovy's UK licence, did not test 1 mg as a stand-alone therapeutic dose for weight loss. The trials ran participants up to 2.4 mg, with the titration steps in between (including 1 mg) treated as dose-escalation stages rather than endpoints. STEP 1, published in the New England Journal of Medicine, found that adults with obesity who reached and maintained 2.4 mg semaglutide lost around 15% of body weight on average over 68 weeks, alongside a reduced-calorie diet and increased activity. The 1 mg week is part of how participants got there. That context matters: if you are currently at 1 mg of Wegovy, the trial data describes what the medicine can do at the destination, not the staging post you are passing through.

The titration schedule set out in the UK Summary of Product Characteristics runs 0.25 mg, then 0.5 mg, then 1.0 mg, then 1.7 mg, then 2.4 mg, each step held for approximately four weeks before the prescriber considers moving up. Some people spend longer at a given step if side effects need more time to settle. The NHS medicines page for semaglutide summarises this schedule clearly and is worth reading alongside any guidance your prescriber gives you.

Why tolerability, not weight loss, is the measure at 1 mg

A question our prescribers hear regularly is whether being at 1 mg means the medicine is not working. The short answer is that at this point in the schedule, tolerability is the test, not the number on the scales. Semaglutide slows gastric emptying and acts on appetite-regulating receptors in the brain, and both effects intensify as the dose rises. The step from 0.5 mg to 1 mg is specifically designed to let the body adjust before the larger increases ahead.

Gastrointestinal side effects (nausea being the most reported, followed by loose stools, constipation and burping) tend to peak shortly after a dose increase and taper off within days to a couple of weeks for most people. If they persist or are severe, that is a conversation to have with your prescriber rather than something to manage alone. Fatigue is also reported during titration; if that's affecting you, the pattern of fatigue at later Wegovy doses is explored separately. Staying at 1 mg is not a failure, it is the schedule working as intended.

The 1 mg pen: what you are actually injecting

Wegovy at 1 mg is supplied as a pre-filled pen containing four weekly doses. The pen stays in the fridge between uses, and most people find keeping it in the fridge door (same shelf, same routine) makes the weekly injection easy to remember. Each dose is injected once a week into the abdomen, thigh or upper arm; rotation of the site matters. The exact storage window for brief room-temperature exposure is stated in the Patient Information Leaflet that comes with your pen; always follow that, not figures quoted online.

The 1 mg Wegovy pen itself has a built-in needle that does not require a separate attachment, and it locks after use. If you have any questions about injection technique, your prescriber or pharmacist is the right person to ask. Dispose of used pens in a sharps container, never in household waste.

What comes next: 1.7 mg, 2.4 mg and the newer 7.2 mg option

After the 1 mg step, the licensed UK schedule moves to 1.7 mg, then to the standard 2.4 mg maintenance dose. In January 2026, the MHRA approved a 7.2 mg dose (initially delivered as three 2.4 mg pens weekly) and in April 2026 approved a dedicated single-dose 7.2 mg pen for adults with a BMI of 30 or above. Trial data for 7.2 mg reported average weight loss of around 20.7% over 72 weeks, bringing semaglutide closer to the results seen with tirzepatide at its highest doses. Whether any of those higher steps are appropriate for you is entirely a clinical decision, and our guide to Wegovy mg options covers what distinguishes each dose from the next.

If you are considering starting Wegovy, the full Wegovy dosing schedule sets out all the steps in one place. The range of treatment options available through a regulated UK online pharmacy, including how to explore whether semaglutide is suitable for you, is covered on our weight-loss treatments page. The Wegovy overview is a good starting point if you want the broader picture before going into the detail of individual doses. For anyone further along and curious about the step above, the next dose up is worth reading too.

These are prescription-only medicines. A real clinician, not software, reads your consultation before anything is prescribed. If you would like to find out whether you are clinically suitable, the first step is a free consultation with our prescribers.