1 ml Semaglutide: What That Volume Actually Means for Your Treatment

Step 1: understand what "1 ml" describes in a semaglutide pen

Semaglutide solution has a concentration, typically expressed as milligrams per millilitre (mg/ml). When someone refers to "1 ml of semaglutide" they're usually quoting the volume of solution that a particular pen cartridge holds, or the volume delivered per injection at a specific dose setting. Neither figure is something a patient controls.

In the Wegovy pen as licensed in the UK by the MHRA, each injection delivers a small, precisely calibrated volume of solution containing the prescribed dose of semaglutide. The pen's internal mechanism handles that calculation. You press the button; the device does the rest. There is no syringe, no vial, no measuring. This matters both for accuracy and for safety: the pre-filled design removes the risk of drawing up the wrong amount.

If a source is offering semaglutide as a multi-dose vial where you measure out 1 ml yourself, that is a significant red flag. The licensed UK product does not work that way, and the MHRA's Yellow Card scheme exists partly so patients can report suspect products of exactly this kind. Vials of "reconstitutable" semaglutide are not MHRA-authorised for weight management and have been associated with enforcement action against illegal sellers. You can read more about semaglutide as a medicine on the semaglutide overview page.

Step 2: follow how the licensed dose schedule is actually structured

The Wegovy dose pathway starts at 0.25 mg once weekly. That's the settling-in stage, its job is to help your body adjust before the therapeutic doses begin. A prescriber then steps you up roughly every four weeks: 0.25 mg, then 0.5 mg, then 1.0 mg, then 1.7 mg, and finally 2.4 mg as the standard maintenance dose.

Since January 2026 there has also been a higher 7.2 mg dose option for Wegovy, and in April 2026 the MHRA approved a dedicated single-dose 7.2 mg pen, one pre-set injection per week, with an auto-dosing mechanism and a built-in covered needle. Clinical trial data for the 7.2 mg dose showed around 20.7% average weight loss over 72 weeks, narrowing the gap with tirzepatide results. The NHS and NHS semaglutide guidance covers the general dose framework, while the exact steps for any individual are a clinical decision.

None of those figures map onto a "1 ml" instruction. The volume delivered per injection varies by dose setting and pen format, and if you are researching specific cartridge sizes you may find it useful to compare options such as our 2 ml semaglutide pen guide, our 3 ml semaglutide pen guide, or our 5 ml semaglutide pen guide, though what matters clinically is the milligram dose, not the millilitre volume. Our Wegovy treatment page has more on how the medicine works.

Step 3: know what the right route to semaglutide looks like in the UK

Wegovy (semaglutide) is a Prescription-Only Medicine. The legal route to it is a clinical assessment with a registered prescriber, followed by a prescription if you're clinically suitable. Adults with a BMI of 30 or above, or 27 or above with a weight-related condition such as high blood pressure, high cholesterol or type 2 diabetes, may be eligible under the licensed criteria, though a prescriber assesses the full picture, not the number alone.

At nume, every consultation is read the same day by a GPhC-registered Independent Prescriber. A real clinician reviews your answers, not software. If you're curious about how that process compares across different treatment options, the weight loss treatments overview sets it out plainly. For anyone researching cost (a question we hear often) the Wegovy cost and access page explains what a legitimate price includes and why a very low figure should prompt caution.

If you're unsure whether a product you've seen online is the genuine licensed medicine, the GPhC pharmacy register lets you verify any online pharmacy in seconds. Our registration number is 9012878, verifiable at pharmacyregulation.org. It's a thirty-second check that's worth doing before placing any order. And if you've come across a vial or unlicensed format, report it via the Yellow Card scheme rather than purchasing.

One practical note: if you're planning to start treatment around a bank holiday or at the end of the month when things tend to pile up, it's worth leaving a few extra days. Orders placed by 12pm on a working day are dispatched the same day once clinically approved, and arrive the next working day via tracked DPD delivery, but bank holidays pause that clock like any other service. You can check current availability through our FAQs or reach the team directly via the contact page.