Weight Loss Injections in St Helens: A Step-by-Step Guide

Step 1: Understanding what these medicines are and how they fit into treatment

Mounjaro and Wegovy belong to a class sometimes called GLP-1 medicines, though Mounjaro is more precisely a dual GIP and GLP-1 receptor agonist. Both are once-weekly subcutaneous injections delivered via a pre-filled pen. The mechanism matters practically: by activating receptors involved in appetite signalling and gastric emptying, they reduce how hungry you feel and how quickly you want to eat again. That effect is pharmacological, not motivational, which is why the evidence from large trials is consistent regardless of individual willpower.

Treatment starts at a low dose to give your body time to adjust. For Mounjaro, that means beginning at 2.5mg (a dose whose main job is tolerability, not weight loss) before stepping up through the schedule your prescriber sets. Wegovy follows a similar stepped approach, starting at 0.25mg. Neither medicine is taken as a fixed single dose from day one, which is one reason clinical oversight throughout the treatment is essential, not optional. If you want to understand the broader category before going further, our page on weight loss injections covers how these treatments work and what using them actually involves.

It's also worth knowing that Ozempic, despite being semaglutide, is licensed for type 2 diabetes, not weight management. Rybelsus is oral semaglutide licensed for diabetes. These are not alternatives to Wegovy for people seeking weight loss treatment; they are different products for a different indication, and neither B12 injections nor unlicensed compounds carry the same evidence base as Mounjaro or Wegovy.

Step 2: Checking whether you're likely to be eligible

The licensed eligibility criteria for private treatment mirror the UK SmPCs: adults with a BMI of 30 or above, or 27 or above with at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea, prediabetes or type 2 diabetes. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance, typically 2.5 kg/m² lower for South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds.

BMI is a starting point, not a decision. A prescriber looks at your full medical picture: existing conditions, current medications, contraindications including a history of pancreatitis or medullary thyroid carcinoma, and whether the risks of treatment are justified by your individual circumstances. Neither medicine is recommended during pregnancy, while breastfeeding, or for anyone trying to conceive, and neither is licensed for under-18s.

On the NHS in St Helens, access to tirzepatide follows NICE's phased rollout under Technology Appraisal 1026. As of June 2025, NHS prescribing for tirzepatide opened to adults with a BMI of 40 or above plus four or more qualifying conditions; from June 2026, that expanded to BMI 35–39.9 with four or more conditions. Criteria will continue widening. Wegovy is available via specialist weight management services under NICE's appraisal TA875, though waiting lists can be lengthy. If you don't meet NHS thresholds, or don't want to wait, a regulated private pharmacy is the other legal route.

Step 3: Getting a prescription through a regulated service

The only legal way to obtain Mounjaro or Wegovy is through a valid prescription, issued by a registered prescriber following a genuine clinical assessment. That assessment can happen in person with a GP, through an NHS specialist service, or via a GPhC-registered online pharmacy. All three routes are legitimate; the key is verifying that the pharmacy you use is registered. You can check any UK pharmacy on the GPhC's public register in under a minute.

At nume, the consultation is free, the prescription is free, and every set of answers is read the same day by a GPhC-registered Independent Prescriber, a real clinician, not automated software. Identity is verified by photo ID, and weight is confirmed on a live video call. If treatment is approved and your order is placed by 12pm on a working day, it's dispatched that afternoon and delivered by DPD the following working day, in plain packaging. Many people store their pen in the fridge door between doses; that works well as a practical prompt, as long as the pen stays at 2–8°C per the Patient Information Leaflet guidance.

For a full breakdown of what private treatment typically costs across providers, our cost guide covers what a legitimate price includes, and what headline figures often leave out.

Step 4: Side effects, safety, and when to get medical help

The most common side effects of both medicines are gastrointestinal: nausea, vomiting, diarrhoea, constipation, indigestion, and burping. These are most noticeable after starting treatment or after a dose increase, and they tend to settle within the first couple of weeks for most people. Taking care to eat slowly and in smaller portions helps reduce the severity.

A smaller number of people experience more significant reactions. The NHS's tirzepatide guidance notes symptoms that need prompt medical attention: severe, persistent stomach pain that spreads to the back (with or without vomiting) may indicate acute pancreatitis, a known though infrequent risk highlighted in a January 2026 MHRA Drug Safety Update on GLP-1 medicines. Gallbladder symptoms, dehydration following serious GI illness, and allergic reactions are also reasons to seek medical help quickly. If you experience low mood or thoughts of self-harm, contact a clinician the same day.

Patients and carers can report any suspected side effects via the MHRA's Yellow Card scheme, which also accepts reports of suspect sellers, useful context given the number of counterfeit pens circulating online. For a deeper look at what the clinical evidence shows on how these medicines compare, our guide to the three main licensed weight loss injections sets it out clearly.

At the end of this process, the question isn't really whether injections to help weight loss work, the trial data published in the New England Journal of Medicine is convincing. The question is whether they're right for you, at this dose, given your health picture. That's a clinical conversation, not a transactional one. Check your eligibility with our prescribers if you'd like to take that step.