Semaglutide B12 Dosage Chart: What the Research Actually Shows

The compounding clinic connection: why a "semaglutide B12 dosage chart" exists at all

In the United States, some private weight-loss clinics have dispensed compounded semaglutide (a version manufactured outside the licensed supply chain) mixed with vitamin B12, vitamin B6 or other additives. These clinics sometimes publish dosing charts showing how many units to draw from a vial alongside a B12 injection. That content travels freely online, and UK readers searching for a dosage chart often land on it without realising it describes something neither licensed nor available in Great Britain.

In the UK, Wegovy is a pre-filled, pre-set pen. There is no vial, no syringe, no ml-to-mg conversion to perform at home, and no B12 in the pen. The semaglutide dosage schedule is set by your prescriber based on your tolerability and clinical history, then confirmed in the Patient Information Leaflet supplied with the pen. Anyone offering a UK patient a "semaglutide B12 combination" through an online seller almost certainly is not operating through the licensed UK supply chain, a serious safety concern the MHRA has warned about repeatedly.

The MHRA's public guidance on GLP-1 medicines makes clear that medicines sold without a valid prescription from an unverified source carry real risks, including contamination and incorrect concentration. If you have seen a dosing chart online and wondered whether it applies to you, it almost certainly does not.

Does semaglutide affect B12 levels, and should you check yours?

This is the legitimate question buried inside the search. Semaglutide slows gastric emptying and, for many people, substantially reduces appetite and overall food intake. Eating less (particularly less meat, fish, eggs and dairy) can reduce dietary B12 over time. There is also early research suggesting GLP-1 receptor agonists may influence gastric acid secretion, which plays a role in releasing B12 from food. The evidence is not yet definitive enough for NICE or the NHS to recommend routine B12 screening for everyone on Wegovy, but it is a reasonable thing to raise with your prescriber, particularly if you follow a vegetarian or vegan diet or have had gut surgery.

Symptoms of B12 insufficiency (fatigue, tingling in the hands or feet, low mood, difficulty concentrating) can overlap with side effects of semaglutide itself, which makes clinical assessment rather than self-supplementation the sensible approach. A blood test costs very little at a GP practice and gives you an actual number to act on. The Wegovy dose schedule page covers the licensed titration steps in more detail, which may help you frame that conversation with your doctor.

If a deficiency is confirmed, your GP will advise on the appropriate form and dose of B12 replacement, oral tablets or intramuscular injections depending on the cause and severity. That decision sits with your clinical team, not with a generic chart.

What the licensed Wegovy dose schedule does look like

Because many people arrive at this page wanting to understand the actual semaglutide schedule, it is worth being clear. Licensed Wegovy (injection) starts at 0.25 mg once weekly. The prescriber moves the dose up roughly every four weeks: 0.5 mg, then 1.0 mg, then 1.7 mg, reaching the 2.4 mg maintenance dose. In April 2026 the MHRA approved a higher 7.2 mg dose in a dedicated single-dose pen, for adults with a BMI of 30 or above; the titration to that level still begins at 0.25 mg, and you can see how each step maps out in the 10 mg semaglutide dosage chart, which covers the higher end of the dose range in detail. For reference on how ml figures relate to these mg doses in research contexts, the semaglutide ml-to-mg page explains the conversion, though it is worth emphasising that with pre-filled UK pens, you never draw or measure a dose yourself.

Through nume (sorry, through our pharmacy) each pen arrives by DPD the next working day in plain, unbranded packaging, with tracking sent to your phone. The pen comes ready to use; the Patient Information Leaflet inside sets out storage, injection technique and what to do if a dose is missed. Dose changes are made only after a clinical review, not automatically. If you are curious about Wegovy pricing in the private market, that page gives honest context on what the cost covers.

Semaglutide is a prescription-only medicine. A prescriber assesses whether it is clinically suitable for you before any treatment begins, eligibility is not decided by a BMI number alone.

Raising nutrient questions with your prescriber, how it works at nume

A question our prescribers hear regularly: "Can I take B12 alongside Wegovy?" The honest answer is that oral B12 supplements are generally low-risk and widely available, but whether you need one, and at what level, is worth confirming rather than assuming. If you are already taking supplements, tell your prescriber during the consultation, it is part of the medical picture.

For people starting treatment or already on it, the weight-loss treatments page is the right starting point for a free consultation. Our prescribers are GPhC-registered; a real clinician reads your answers the same day, not software. Aftercare is available seven days a week if a question comes up mid-treatment, including questions about nutrition, monitoring or what to do if you are not feeling well on your current dose. You can also browse the FAQs for answers to common questions before you begin.

The NHS's own guidance on semaglutide side effects and how to take it is a reliable first reference. For the clinical evidence behind the licensed dose schedule, NICE's appraisal of semaglutide for weight management (TA875) sets out the framework UK prescribers follow.