Weight loss injections on the Wirral: the practical guide

What do these injections actually do in the body?

Mounjaro and Wegovy belong to a family of medicines called GLP-1 receptor agonists. They work by mimicking gut hormones that regulate appetite and blood-sugar levels, making the brain receive stronger satiety signals after meals and slowing the rate at which the stomach empties. The practical effect is that most people find their appetite falls noticeably, and meals that once felt modest become genuinely filling. Mounjaro goes a step further by also activating a second receptor (GIP) making it the only dual-agonist weight-loss medicine licensed in the UK. How each injection works at a biological level is covered in more depth in our treatment guide, but the short version is that neither medicine burns fat directly: they change the hormonal environment that drives hunger.

In clinical trials, the effects were substantial. The SURMOUNT-1 trial, published in the New England Journal of Medicine, reported average body-weight reductions of around 20–21% over 72 weeks at the highest tirzepatide dose, with participants following a reduced-calorie diet and increased activity alongside treatment. Semaglutide 2.4mg produced around 15% average reduction over 68 weeks in its STEP 1 trial. These are averages from carefully monitored trials; individual results vary, and a prescriber will help you set realistic expectations.

Both medicines are given as a once-weekly subcutaneous injection, a very short, fine needle into the skin of the abdomen, thigh or upper arm, rotated each week. If you are researching the full range of injectable options available in the UK, you can read about the Majorino weight loss injection and how it compares to other treatments on its dedicated page. Most people describe the injection itself as virtually painless once they have done it two or three times.

Does living on the Wirral affect how you can access these medicines?

Not in the way you might expect. NHS access to weight loss injections is restricted nationally, and the Wirral is no exception. NICE has recommended tirzepatide and semaglutide under specific eligibility thresholds (criteria that include BMI bands and the presence of certain weight-related conditions) and NHS England is rolling out access in phases. Getting started without a GP referral is possible through a regulated private route, and that route works from any address in England.

Privately, eligibility follows the licensed criteria set out in each medicine's summary of product characteristics: adults with a BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as high blood pressure, high cholesterol, type 2 diabetes or obstructive sleep apnoea. Lower thresholds apply for some ethnic backgrounds under UK guidance. Your postcode has no bearing on whether you qualify, the assessment is clinical, based on what you share in your consultation.

At nume, the process works entirely online. You complete a structured health questionnaire, verify your identity by photo ID, and confirm your current weight on a brief video call. A GPhC-registered Independent Prescriber (a real clinician, not an automated system) reads your answers and either approves, declines or asks follow-up questions the same day. There are no waiting lists and no requirement for a GP letter. If you order before 12pm on a working day and your consultation is approved, your treatment is dispatched the same afternoon.

What side effects should Wirral patients know about before starting?

The most common side effects of both Mounjaro and Wegovy are gastrointestinal. Nausea is the one people mention most; loose stools, constipation, indigestion and fatigue are also reported, particularly in the first few weeks of treatment or after a dose increase. For most people these settle within a fortnight as the body adjusts, and starting at the lowest dose (2.5mg for tirzepatide; 0.25mg for semaglutide) is specifically designed to give your system time to adapt before the dose moves up.

Rarer but more serious effects deserve attention. In January 2026, the MHRA issued a Drug Safety Update highlighting acute pancreatitis as an infrequent but potentially serious risk with GLP-1 medicines: seek urgent medical attention for severe stomach pain that spreads to the back, especially if it comes with vomiting. The MHRA Yellow Card scheme lets patients report any suspected side effect directly, and our prescribers encourage patients to do so.

Women using oral contraceptives who start tirzepatide should add a barrier method for the first four weeks of treatment and for four weeks after each dose increase, because the pill's absorption may be reduced; NHS guidance notes no equivalent evidence for semaglutide. Pregnancy, breastfeeding and trying to conceive are contraindications for both medicines; the same applies to patients under 18. Before any surgery, tell your anaesthetist that you are taking a GLP-1 medicine. The NHS tirzepatide patient information page is a reliable reference for the full list of side effects and precautions in plain language.

How much does private treatment cost, and what does the price include?

Private weight loss injection costs vary by medicine, dose and provider. Since Eli Lilly raised Mounjaro's UK list price in September 2025, typical private prices across the market have ranged roughly £149–£375 per month depending on dose and where you go. That range is widely reported and hedged here because individual quotes differ. What varies even more than the headline figure is what is actually included. Some providers charge separately for the consultation, the prescription and delivery; some require a subscription you cannot pause.

You can explore how treatment costs break down in detail on our cost guide. At nume, the price you see covers the consultation, the prescription, the medicine and free tracked next-working-day delivery, nothing is added at checkout, and there is no subscription. We are not positioning ourselves as the cheapest option available; we are positioning ourselves as a fully included, clinically supervised one. A Wirral patient who wants to understand the full picture of what they are paying for, before committing, is exactly who that structure suits.

Ready to find out whether you're clinically suitable? Start your free consultation and a GPhC-registered prescriber will review your case the same day.