How to Reconstitute 10mg Semaglutide — and Why That Question Has a Concerning Answer

The misconception: that reconstituting semaglutide powder is a normal part of treatment

It isn't. This is the most important thing to correct clearly. When Wegovy is dispensed through a GPhC-registered UK pharmacy (the only legal route for private supply) it arrives as a pre-filled, pre-set injection pen. The semaglutide solution is already inside. You do not open a vial, add bacteriostatic water, draw up a dose, or reconstitute anything. That entire process simply does not apply to the licensed product.

The reason reconstitution instructions circulate online is that a parallel market exists in compounded semaglutide powder and unlicensed vials, often sold through social media or websites operating outside the regulated UK supply chain. These products are not approved by the MHRA for weight management. They are not subject to the manufacturing standards that govern licensed medicines. And the guidance people find about "reconstituting 10mg semaglutide" typically describes how to handle these unapproved preparations, not Wegovy.

A 10mg figure is itself a signal worth noting. Wegovy's licensed UK dosing schedule runs from 0.25mg up to a 2.4mg weekly maintenance dose, with a higher 7.2mg dose approved by the MHRA in 2026 for eligible adults. A "10mg" preparation sits outside the licensed dose range and is not a Wegovy product. The NHS semaglutide medicine page sets out what the licensed product involves for patients.

What the MHRA has actually said about semaglutide products sold outside the licensed supply chain

The MHRA has been direct and public about this. Following a series of enforcement operations, the regulator warned that fake weight-loss injection pens (including counterfeits of branded semaglutide products) had been seized across the UK. Some contained insulin instead of the stated active ingredient, with genuine potential to cause life-threatening hypoglycaemia in people who have no diabetes. Around 20 million doses of illegally traded weight-loss medicines, with an estimated street value of around £45 million, were seized through 2025 enforcement activity.

Products requiring reconstitution are a characteristic of this unregulated market, not of legitimate supply. If a seller has provided you with a powder vial and instructions to mix it yourself, that product has not been through the MHRA-regulated supply chain. You can (and should) report it at yellowcard.mhra.gov.uk, which handles both suspected side effects and suspect sellers.

Verifying a pharmacy before ordering is straightforward. Every legitimate online pharmacy dispensing prescription medicines in the UK appears on the GPhC register, searchable at pharmacyregulation.org/registers. A seller who cannot be found there should not be supplying prescription medicines to you.

What legitimate Wegovy treatment actually looks like in practice

Licensed Wegovy is a once-weekly subcutaneous injection using a pre-filled pen. The titration schedule (starting low to let your system adjust, then increasing in steps over several months) is managed by your prescriber. Patients do not calculate doses, mix solutions or self-titrate without clinical input. Each dose comes preset. You choose an injection site (abdomen, thigh or upper arm), clean the skin, inject, and that's the week's treatment done.

For context on what the dose steps look like and how they differ from unlicensed preparations, the Wegovy doses page covers the licensed schedule clearly. Storage is in the fridge at 2–8°C; the exact room-temperature window if you're travelling is in the patient information leaflet, worth reading before your first holiday with the pen in your bag.

If you're also curious about oral semaglutide, which has its own distinct preparation and administration requirements, that's a separate licensed product; the Wegovy overview covers both injection and tablet forms. For a sense of what private treatment costs through a legitimate service, the Wegovy prices page explains what a transparent, all-inclusive price should cover.

If you already have a product that requires reconstitution

Don't use it without speaking to a healthcare professional first. The risks are not theoretical: wrong concentrations, contamination during mixing, and the possibility that the product contains something other than semaglutide are all real concerns documented by regulators. If you have been given a 5mg semaglutide reconstitution guide alongside a powder vial, that alone indicates the product is not part of the licensed Wegovy supply chain. A pharmacist or GP can advise you without judgment, and reporting the seller helps protect other people from the same risk.

If you want to start semaglutide treatment properly, the route begins with a clinical assessment. A prescriber (a real person, not an automated system) reviews your health history, weight and circumstances before any prescription is issued. At nume's consultation that review happens the same day, by a GPhC-registered Independent Prescriber. Our clinical team is available for questions seven days a week. If you're unsure where to start, the FAQs page covers the most common questions about the process, including a semaglutide B12 dosage chart for patients whose prescription includes a B12 supplement alongside their treatment. You can also contact us directly if you have a specific concern about a product you've already received, including questions about how to reconstitute 5mg semaglutide if you have been supplied an unlicensed preparation and need safe guidance before speaking to a clinician.