Private Weight Loss Injections in the UK: A Clear, Honest Guide to Mounjaro and Wegovy

If you are looking into private weight loss injections in the UK, you probably already know the short version: the two you will keep hearing about are Mounjaro (tirzepatide) and Wegovy (semaglutide), they are prescription-only medicines, and you can access them through a regulated online pharmacy without a GP referral. Prices start from around £125 a month for Mounjaro and £80 for a first month of Wegovy at The Weight Clinic. What most pages skip is the detail that actually helps you decide: how the two medicines differ, who is clinically suitable, what the honest side-effect picture looks like, and how to tell a legitimate service from a risky one.

This guide walks through all of that in plain English, with every efficacy and eligibility figure tied to a named source. These are effective medicines used by hundreds of thousands of people in the UK, but they are also serious ones, and the right starting point is understanding them properly before you fill in a single form.

Why people go private for weight loss injections

The NHS does prescribe these medicines, but access is tightly rationed. Wegovy on the NHS is provided through specialist weight-management services rather than routine GP prescribing, and NHS access to Mounjaro is being phased in gradually through GP prescribing over several years, prioritising people with the highest BMI and the most weight-related illness first (NICE). For many people who are clinically eligible under the medicines' own licences, the NHS route simply is not open yet, or comes with a long wait.

Going private closes that gap. A regulated online pharmacy can assess you against the medicine's licensed criteria rather than the narrower NHS-funding cohorts, review your history remotely, and dispatch treatment directly to your door. You pay the full cost yourself, and in return you get faster access, a consultation you can complete from home, and continuity with one prescribing team. It is not a shortcut around clinical checks, though. A legitimate private service applies the same safety standards as any other prescriber; the difference is speed and eligibility breadth, not a lowering of the bar.

Mounjaro vs Wegovy: what actually separates them

Both medicines are weekly self-injections, both work by mimicking gut hormones that control appetite and blood-sugar, and both are used alongside a reduced-calorie diet and more activity. The practical difference is how many hormone pathways each one targets, and that shows up in the trial data.

Wegovy (semaglutide) acts on a single receptor, GLP-1. In the STEP-1 trial, adults without diabetes taking the 2.4 mg dose lost an average of around 14.9% of their body weight over 68 weeks, compared with about 2.4% on placebo (New England Journal of Medicine, STEP-1).

Mounjaro (tirzepatide) is a dual agonist, acting on both GLP-1 and a second hormone, GIP. In the SURMOUNT-1 trial, adults without diabetes on the 15 mg dose lost an average of around 22.5% of their body weight over 72 weeks (New England Journal of Medicine, SURMOUNT-1).

Those are averages from the highest maintenance doses in tightly controlled trials, not promises. Real-world results vary a great deal depending on your starting point, how your body responds, and how the medicine is combined with changes to how you eat and move. A higher trial average does not automatically make Mounjaro the right choice for you; tolerability, medical history, and cost all feed into the decision, which is exactly what a prescriber's assessment is for. For a fuller side-by-side, see our Mounjaro vs Wegovy comparison.

If you would rather avoid needles entirely, there are also oral options emerging, including oral semaglutide and the newer non-peptide tablet Foundayo. Injections remain the most established route for now, but it is worth knowing the alternatives exist.

Who is eligible for private weight loss injections

Eligibility is a clinical decision, and a genuine service will decline people for whom the risks outweigh the benefits. Under their UK licences from the Medicines and Healthcare products Regulatory Agency (MHRA), these medicines are indicated for adults with a BMI of 30 or above, or a BMI of 27 or above where there is at least one weight-related health condition such as high blood pressure, type 2 diabetes, high cholesterol, or obstructive sleep apnoea (electronic Medicines Compendium, Mounjaro SmPC). These are the licence thresholds, which are broader than the stricter cohorts NHS funding tends to prioritise.

BMI is only the entry gate. Some conditions make these medicines unsuitable regardless of weight. A prescriber will not proceed if you are pregnant, trying to conceive, or breastfeeding, or if you have a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. A history of pancreatitis, certain gallbladder or thyroid conditions, and some other diagnoses also need careful review. This is why honest answers on the consultation matter more than anything: withholding a condition to get a "yes" removes the one safeguard that is there to protect you.

You can get a sense of where you stand before committing to anything by using our eligibility check, or read the more detailed breakdown in Am I eligible for Mounjaro?.

What private weight loss injections cost

Cost is where a lot of providers stay vague, so here is the direct answer for The Weight Clinic. Mounjaro starts from £125 a month. Wegovy is £115 for a standard month, with £35 off your first order using the code NEWME, which brings a first month to £80. The eligibility check itself is free, and there is no subscription or membership fee, so you order when you need to and stop whenever you choose.

A few things are worth building into your budget:

• Dose changes the price. Both medicines start low and step up over the first months (more on that below), and higher doses generally cost more, so your monthly spend is not fixed from day one.
• It is a longer-term commitment. The trial results above came from 68 to 72 weeks of continuous treatment. Weight tends to return if the medicine is stopped abruptly without other changes in place, so it is realistic to plan for months, not weeks.
• Suspiciously cheap is a warning sign. Pens sold well below the market rate, especially through social media, are frequently counterfeit or unlicensed. The regulated cost reflects genuine medicine, prescriber oversight, and temperature-controlled dispatch, none of which is optional.

How it works at The Weight Clinic

The Weight Clinic is a GPhC-registered UK online pharmacy, with treatment overseen by our clinical team including Superintendent Pharmacist Andrew Lane and Pharmacist Independent Prescriber Fatma Al Sibahi. The process is built around a proper clinical assessment rather than a checkout.

1. Free eligibility check. You answer questions about your height, weight, medical history, and current medicines. It takes a few minutes and costs nothing.
2. Prescriber review. A UK-registered prescriber reads your answers and decides whether treatment is clinically appropriate and, if so, which medicine and dose. If it is not right for you, we will tell you, and explain why.
3. Dispensing and delivery. If approved, your medicine is dispensed and sent in temperature-controlled packaging that keeps the pens within their required range in transit.
4. Ongoing support. You reorder when you need to, step up your dose on the agreed schedule, and can reach the pharmacy team with questions along the way. No lock-in, no rolling contract.

If you want to see whether treatment is suitable for you, the free eligibility check is the place to start. For a wider look at what is available, our weight loss injections and treatments pages set out the full range.

Dosing and what the first months feel like

These medicines are not started at full strength. The dose is increased slowly, a process called titration, to let your body adjust and to keep side effects manageable.

Mounjaro starts at 2.5 mg once weekly for at least four weeks, then increases in 2.5 mg steps at intervals of no less than four weeks, up to a maximum of 15 mg weekly, with the maintenance dose set by your prescriber based on how you respond and tolerate it (Mounjaro SmPC). Wegovy follows a similar stepped approach, beginning at 0.25 mg once weekly and increasing at roughly four-week intervals through 0.5 mg, 1 mg, and 1.7 mg to the 2.4 mg maintenance dose. In both cases the first dose is deliberately below the level that drives most of the weight loss; its job is to introduce the medicine gently.

The most common side effects of both medicines are gastrointestinal: nausea, constipation, diarrhoea, and indigestion, usually most noticeable in the first weeks and after each dose increase. For most people these ease as the body adapts, and the slow titration is precisely what keeps them tolerable. Our Mounjaro dosage guide sets out the full schedule if you want the specifics.

Serious side effects are much rarer, but they are real and worth knowing. Pancreatitis (inflammation of the pancreas) can occur: sudden, severe, persistent abdominal pain, especially if it spreads to your back or comes with vomiting, needs urgent medical attention. Gallbladder problems, including gallstones, are also recognised and can be more likely during rapid weight loss. Because these are prescription-only medicines, they are supplied only after a prescriber has weighed these risks against the benefits for you specifically, which is why the contraindications above (medullary thyroid carcinoma, MEN2, a history of pancreatitis, and pregnancy or breastfeeding) are taken so seriously.

Read the patient information leaflet that comes with your pen, and take any severe or unexpected symptom seriously rather than pushing through it. If you experience a side effect you think may be linked to your medicine, you can report it through the MHRA Yellow Card scheme, which the Medicines and Healthcare products Regulatory Agency uses to monitor the ongoing safety of medicines in the UK. Reporting helps protect other patients as well as improving what is known about these treatments.

Spotting a safe provider from a risky one

Because demand is high, the market has attracted sellers who cut corners or sell outright fakes. A few checks separate a regulated pharmacy from a gamble:

• A registered pharmacy. Legitimate UK online pharmacies are registered with the General Pharmaceutical Council and display verifiable registration. If you cannot confirm a registration, treat that as a stop sign.
• A real clinical barrier. You should not be able to add a prescription-only medicine to a basket and pay without a thorough medical questionnaire reviewed by a prescriber. If a site lets you buy without that assessment, it is operating unlawfully and unsafely. There is no legitimate way to buy these medicines without a prescription.
• Proper cold-chain dispatch. These pens must be kept refrigerated between 2°C and 8°C, and shipped in medical-grade insulated packaging. A pen that arrives in a plain envelope, or noticeably warm, should not be used.
• Prices that make sense. If a price looks too good to be true, it almost certainly is.

How it fits with the rest of your life

The trial results were achieved alongside diet and activity support, not instead of it. The medicine does a lot of the heavy lifting by turning down appetite and the constant background pull toward food, which makes eating differently far more achievable, but the eating differently still has to happen. Protein, fibre, hydration, and some regular movement all help you get more from treatment and hold onto the results. Think of the injection as the thing that finally makes sustainable change realistic, not as the whole plan by itself.

If injections are not for you, it is worth revisiting the oral options, oral semaglutide and Foundayo, which offer the same underlying approach in tablet form.

The bottom line is straightforward. Private weight loss injections in the UK give clinically eligible adults a faster, regulated route to two well-evidenced medicines, at a transparent monthly cost, with no subscription. Whether one of them is right for you is a question for a prescriber, and the honest, no-obligation way to find out is a free eligibility check.