Getting a weight loss injection from a GP: what your options actually look like

What your GP can and cannot currently do

The short answer is that your GP might be able to help, but the odds depend heavily on which practice you attend and whether you clear a high eligibility bar. From 1 April 2026, GP practices in England have been able to prescribe tirzepatide for weight management under a new contract arrangement. Participation is voluntary, though, so some practices have signed up and others have not. If yours has, your GP will check whether you meet NICE's criteria for tirzepatide: a BMI of 35 or above, plus at least one qualifying condition such as high blood pressure, type 2 diabetes, dyslipidaemia, obstructive sleep apnoea, or cardiovascular disease. The current NHS cohort being treated has four or more of those conditions alongside a BMI of 40 or above, a group that represents a small fraction of people who feel weight is affecting their health.

For semaglutide (Wegovy), the NHS route runs through specialist weight management services rather than GP surgeries. Those services have waiting lists that commonly stretch into months or longer. Whether your GP can refer you will depend on local commissioning and whether your BMI and comorbidity profile meets the service's intake criteria. GP-prescribed weight loss injections are a real option for some people, just not for most, right now.

None of this means your GP is the wrong first call. If you have a long-term condition that might qualify you, talking to them costs nothing and could open the NHS route. Worth checking before exploring alternatives.

Why BMI alone does not settle the question

A BMI of 30 is the private licensed threshold for both Mounjaro and Wegovy, or 27 if you have a weight-related condition. That sounds simple, but BMI is one part of a broader clinical picture. A prescriber will also consider your other medications, your GI history, kidney and liver function, whether you are pregnant or planning a pregnancy, and a handful of contraindications that apply regardless of how your weight sits on a chart.

The NICE appraisal of tirzepatide (TA1026) sets its own eligibility criteria for NHS use, which are more restrictive than the licensed private criteria. Weight loss injections on the NHS are deliberately rationed during this phased rollout, because the treatment population that would benefit is far larger than current supply and commissioning can accommodate. The private licensed criteria, set out in the medicines' summaries of product characteristics, are broader, and that is the framework a private prescriber applies.

Lower BMI thresholds can apply for people from South Asian, Chinese, Middle Eastern, Black African, or African-Caribbean backgrounds under UK clinical guidance, reflecting different cardiometabolic risk profiles at lower body weights. A good prescriber will apply this rather than defaulting to the standard numbers.

Side effects, storage, and what life with a weekly injection looks like

Both medicines are once-weekly injections. Tirzepatide comes as a pre-filled KwikPen with four doses; semaglutide (Wegovy) as individual pre-filled pens. The injection goes under the skin at the abdomen, thigh, or upper arm, with the site rotated each week. Most people keep their pens in the fridge door and set a day-of-week routine early (Tuesday morning before work, say) which makes missing doses much less likely.

The most common side effects are gastrointestinal: nausea, loose stools, constipation, and sometimes reflux, particularly in the early weeks or after a dose increase. These are not trivial for everyone, but they typically ease as the body adjusts. Serious effects are uncommon but real, the full picture of side effects from weight loss injections is worth reading carefully before you start, especially the signs that warrant prompt medical attention. The NHS tirzepatide medicine guide lists common and serious side effects alongside the patient information leaflet, which is the definitive reference for your specific pen.

Both pens require refrigeration; there is a limited window for room-temperature storage that the patient leaflet sets out precisely. Travel needs a little planning, but it is manageable.

What the private route actually involves, and what to look for

If your GP cannot prescribe (or you would rather not wait) a regulated private online pharmacy is the established alternative. The clinical process should be substantively the same: a structured consultation, identity verification, and a real prescriber reviewing your answers before any prescription is written. Getting weight loss injections from a doctor privately differs from the NHS mainly in speed and cost, not in safety standards.

At nume, every consultation is read the same day by a GPhC-registered Independent Prescriber, a named clinician, not an automated system. Photo ID, live video weight verification, and GP notification sit behind every approval. You can check our pharmacy on the GPhC register (registration number 9012878) at pharmacyregulation.org, that five-second check is the clearest signal that any online service is operating legitimately. For a weight loss injection that is a prescription-only medicine, that verification matters more than almost anything else you will read in a website's marketing.

The cost of private treatment varies by dose and provider, that page gives an honest picture of what the market looks like and what a transparent price should include. For a full overview of how to get weight loss injections through each route, that guide covers the NHS and private pathways side by side. Our clinical team at nume is here if you have questions before you start.