500 mcg Semaglutide: Clearing Up a Common Dose Confusion

The misconception: 500 mcg as a semaglutide weight-loss dose

Search engines surface "500 mcg semaglutide" because the figure appears in some diabetes-prescribing contexts and older oral formulation research, and it occasionally makes its way into forum discussions. But in the UK weight-loss landscape it is simply not a licensed step. The Wegovy injection programme runs in milligrams, not micrograms, and neither 0.5 mcg nor 500 mcg appears anywhere in the approved titration ladder for weight management.

This matters for a practical reason: people who arrive at a pharmacy or an online consultation expecting a 500 mcg option may be comparing against dosing information from another country, another indication (type 2 diabetes), or (more worryingly) an unlicensed seller. None of those sources are a reliable guide to what you should actually be taking in the UK.

The licensed Wegovy injection schedule, as set out in the SmPC and summarised by the NHS semaglutide medicines page, progresses through five distinct doses over roughly 16 weeks before reaching the 2.4 mg maintenance dose. Every step upward is a clinical decision, not an automatic progression.

Why the dose ladder is shaped the way it is, and where 0.5 mg fits

A question our prescribers hear most weeks is some version of: "Why do I have to start so low?" The answer is gastrointestinal tolerance. Semaglutide slows gastric emptying and reduces appetite strongly enough that jumping to a therapeutic dose without acclimatisation causes significant nausea, vomiting and discomfort in a large proportion of people. The graduated steps exist to let your digestive system adjust gradually.

The 0.5 mg step (500 mcg, if you prefer that unit) does exist within the schedule, but as the second dose in the injection titration, taken during weeks five to eight, after the 0.25 mg starter month. It is not a target dose or a maintenance level; it is a rung on a ladder that continues to climb. Patients who stay at 0.5 mg for an extended period are not on a therapeutic maintenance dose, they are mid-titration, and continuing to the higher doses is part of the plan where clinically appropriate.

If you are curious about how the full programme compares across doses, the 1 mg semaglutide page covers what that step involves and when it is reached in the schedule.

Oral semaglutide uses a completely different scale

Wegovy tablets (approved by the MHRA on 11 June 2026 as the UK's first oral GLP-1 medicine licensed for weight management) use a dose scale that looks nothing like the injection schedule. The progression runs 1.5 mg, which you can read about in detail on our dedicated 1.5 semaglutide page, 4 mg, 9 mg and up to 25 mg daily. These higher numbers are not a stronger version of the injection; they reflect the fact that oral absorption of semaglutide is far less efficient than subcutaneous injection, so considerably more of the compound must be delivered to achieve a comparable effect at the receptor level.

The practical upshot is that a "500 mcg" query could theoretically touch both the injection mid-titration rung and the territory between the 0.25 mg oral starter and the next oral step, but in neither case does 500 mcg describe a recognised UK licensed dose for weight loss. If you want to understand how the higher oral doses are structured, our semaglutide 2 page explains what that stage of the oral titration involves and where it sits in the overall schedule.

Understanding the cost implications of the full treatment course is worth thinking through early. Our guide to Wegovy costs in the UK sets out what transparent private pricing typically includes and what to watch for when comparing providers.

What this means in practice when you speak to a prescriber

When you go through a clinical consultation for semaglutide weight management, your prescriber works from the licensed UK schedule, not from a dose you have read about elsewhere. They will review your health history, current medicines, BMI, and weight-related conditions before confirming suitability. If semaglutide is appropriate, treatment begins at 0.25 mg; dose increases happen at intervals and only when your prescriber is satisfied you are tolerating the current dose and making progress.

The broader semaglutide overview covers eligibility, mechanism and the evidence base in more depth if you want to read further before starting a consultation. Wegovy (injection and tablets) is a Black Triangle medicine, meaning the MHRA requires additional post-marketing surveillance, another reason why the prescribing pathway is intentionally structured and supervised.

If you are ready to find out whether semaglutide is clinically suitable for you, start your free consultation and a GPhC-registered prescriber will review your details the same day.