Weight Loss Injections in Harrow: A Practical Guide

Step 1, Complete a clinical consultation (this is where eligibility is decided)

The first thing to understand is that neither Mounjaro nor Wegovy can be handed over the counter or posted to you without a prescription from a qualified prescriber. That is not a technicality; it is the law under the Human Medicines Regulations 2012, and it exists because these medicines affect your hormonal and digestive systems in meaningful ways that vary person to person.

Your consultation covers the things a prescriber needs to know: your current BMI, any weight-related conditions you have (such as high blood pressure, type 2 diabetes, high cholesterol or obstructive sleep apnoea), your medication list, and your medical history. The licensed threshold for both injections is a BMI of 30 or above, or 27 and above if you have at least one qualifying condition. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. None of those numbers guarantees approval on their own, a prescriber weighs the full picture. The process of getting a weight loss injection prescription is straightforward when you go through a regulated pharmacy, but it does involve that clinical gate.

At nume, a GPhC-registered Independent Prescriber reads every consultation personally, a real clinician, not automated decision software. If you order on a weekday before noon, that review happens the same day.

Step 2 (Understand what these medicines actually do in your body

Mounjaro is a dual GIP and GLP-1 receptor agonist) the only one licensed for weight management in the UK. It activates two gut-hormone pathways involved in appetite regulation and blood-sugar control, and it slows gastric emptying so meals feel satisfying for longer. Wegovy acts on a single pathway (GLP-1 only) but through a similar principle. The NHS has a clear patient-level explanation of how tirzepatide works if you want to read the mechanism in plain language before your consultation.

Neither medicine is a quick fix. The clinical trials that informed NICE's guidance ran for 68–72 weeks, with participants making dietary and lifestyle changes alongside the medicine. SURMOUNT-1 (the pivotal tirzepatide trial) involved around 2,500 adults and reported an average body-weight reduction of roughly 20–21% at the highest dose over 72 weeks. That figure is meaningful, but it comes from a structured programme, not from the pen alone.

Side effects are real and worth knowing about before you start. The most common are gastrointestinal: nausea, loose stools, constipation, reflux and burping. They tend to be most noticeable when you begin treatment or move up to a new dose, and for most people they ease within a couple of weeks. Our guide on why these injections cause nausea explains what is happening and what can help.

Step 3 (Injecting safely and storing your pen correctly

Both Mounjaro and Wegovy are once-weekly subcutaneous injections) meaning just under the skin, not into a muscle. Suitable sites are the abdomen, the outer thigh, and the upper arm; you rotate between them to avoid skin reactions building up in one spot. The technique is simpler than most people expect, and the pre-filled pen does most of the work. A full walkthrough of how to administer a weight loss injection covers positioning, the cap sequence and what to do afterwards.

Storage matters. Both pens need to be kept refrigerated at 2–8°C until you are ready to use them. There is a limited window during which a pen can be kept at room temperature, for exact figures, your Patient Information Leaflet is the definitive source, not the internet. If you are planning a holiday or a trip away from home over a long weekend, think about where refrigeration will come from before you order. Payday orders or Monday morning starts are popular for a reason: a stable routine at home makes that first week easier to navigate.

Used pens and needles are clinical waste and cannot go in the household bin. A sharps container keeps disposal safe and compliant; local councils and pharmacies usually offer collection.

NHS versus private: what that means for Harrow residents

NHS access to these medicines in Harrow follows national England criteria, which are phased. As of June 2025, NHS tirzepatide was available for adults with a BMI of 40 or above plus four or more qualifying conditions. A second cohort (BMI 35–39.9, four or more conditions) opened in June 2026. Those thresholds will widen gradually over the coming years, but waiting lists in specialist services are commonly long, and not every GP practice has opted into the new prescribing arrangement under the 2026 QOF contract. If you would like to understand which 3 weight loss injections are currently available in the UK and how they compare under those criteria, the NHS England guidance on weight management injections sets out the criteria in detail.

Private treatment through a regulated pharmacy is the alternative for people who do not meet the current NHS thresholds or who would rather not wait. If you are exploring that route, the right question to ask is not which service is cheapest, it is whether the service uses a GPhC-registered pharmacy, whether a named prescriber reviews every consultation, and whether your supply comes through the licensed UK chain. You can verify any online pharmacy on the GPhC register; for reference, nume's registration number is 9012878. For a fair picture of what private treatment tends to cost, the weight loss treatment overview covers pricing context honestly.

If you want to read more about the people behind the clinical decisions at nume our clinical team page is a good place to start. When you feel ready, you can read about which weight loss injections are available through nume, or explore how to choose the right weight loss injection for your circumstances, before checking your eligibility through a free consultation with no obligation.