Mounjaro and Wegovy are weekly self-administered injections approved by the MHRA for weight management in the UK. They work by mimicking natural gut hormones that regulate hunger, blood sugar, and digestion, helping you feel full sooner and stay satisfied longer.
They are not appetite suppressants in the traditional sense. They change how your body signals hunger at a hormonal level, which is why results tend to be more sustained than older methods.
Both are prescription-only. A clinical assessment is required before starting, and neither is available over the counter. Pharmacy M offers weight loss treatments including Mounjaro, Wegovy, Mysimba, and Orlistat, depending on what suits your profile.
Mounjaro vs Wegovy: Key Differences at a Glance
Both injections are effective, but they work slightly differently. The right one depends on your health profile, goals, and how your body responds.
How Mounjaro Works
Mounjaro (tirzepatide) targets two hormones, GLP-1 and GIP. This dual action reduces appetite, slows digestion, and improves how your body manages insulin. Clinical trials showed average weight loss of up to 22% of body weight over 72 weeks.
How Wegovy Works
Wegovy (semaglutide) acts on GLP-1 receptors only. It signals fullness to the brain and slows gastric emptying. STEP trials showed around 15% average body weight reduction. It is also NICE-approved for NHS use in specialist settings, though access remains limited for most people.
The dual-action mechanism behind Mounjaro is what sets it apart from semaglutide-based treatments and often explains why weight loss outcomes differ between the two.
Who Qualifies for a Weight Loss Injection?
Both Mounjaro and Wegovy are clinically indicated for adults who meet specific criteria. Your pharmacist will confirm eligibility at your consultation.
You are likely eligible if you have:
- A BMI of 30 or above, or
- A BMI of 27 or above with a weight-related condition such as type 2 diabetes, high blood pressure, or high cholesterol
They are not suitable if you are pregnant, breastfeeding, or have a personal or family history of certain thyroid conditions. Your prescriber will review your full health history before anything is issued.
Getting a Private Prescription: Cost and Process
Weight loss injections are not currently available through NHS GP practices for general use. Most people access them through a private prescription, which is faster and requires no GP referral.
What Does a Private Prescription Cost in the UK?
Private prescription charges are not capped the way NHS prescriptions are. The cost covers the medication plus a consultation or dispensing fee. At Pharmacy M, all pricing is confirmed upfront before you commit.
As a general guide:
- Mounjaro: typically £149 to £229 per month depending on dose
- Wegovy: typically £195 to £295 per month depending on dose
- Costs increase gradually as doses step up during the titration period
All costs are discussed at consultation. There are no hidden charges.
What to Expect at Your First Pharmacy Appointment
Your first appointment is a consultation, not just a prescription pickup. Here is what happens:
- Health review – weight, BMI, medical history, and current medications
- Eligibility confirmed – your pharmacist checks you meet the clinical criteria
- Medication selected – Mounjaro or Wegovy recommended based on your profile
- Prescription issued – same appointment, no GP letter needed
- Injection training – you will be shown exactly how to administer at home
- Follow-up planned – a check-in is typically scheduled after four weeks
The whole process takes around 20 to 30 minutes. Walk in or book online at a time that suits you.
How Long Before You See Results?
Most people notice a reduction in appetite within the first one to two weeks. Visible weight loss typically begins around week four and builds steadily over the following months.
Expect a gradual dose increase over 16 to 20 weeks. This titration period helps your body adjust and reduces the likelihood of side effects. The most significant results are usually seen between months three and six.
The week-by-week dosing schedule follows a structured titration pattern, starting at the lowest dose and increasing only when your body is ready.
Side Effects: What’s Normal?
Side effects are common in the first few weeks, particularly as your dose increases. Most are mild and settle on their own.
- Common: nausea, constipation, reduced appetite, mild fatigue
- Less common: vomiting, indigestion, loose stools
- Seek advice: severe or persistent abdominal pain, contact your pharmacist or GP
Eating smaller meals, staying hydrated, and avoiding high-fat foods can help manage early symptoms. Your pharmacist will walk you through this at your first appointment.
Why Choose a Local Pharmacy Over an Online Clinic?
Online clinics offer convenience, but they often lack the face-to-face support that makes a real difference over months of treatment.
At a local pharmacy you get:
- A real person to ask questions, before, during, and between doses
- Same-day appointments with no waiting lists
- Prescription issued and medication dispensed in one visit
- Ongoing monitoring and dose adjustments as needed
- Discreet, private consultations in a familiar and trusted setting
If something feels off at week six, you can walk in. With an online clinic, you fill in a form and wait. Pharmacy M also runs NHS Pharmacy First consultations for common conditions, so ongoing health support is always available alongside your treatment.
Ready to Start? Book Your Weight Loss Consultation
Mounjaro and Wegovy are prescription-only, but getting started is simpler than most people expect. A single appointment at Pharmacy M covers everything, consultation, prescription, and your first dose.
No GP referral. No waiting list. Clear pricing from the start.
Book online or walk in to Pharmacy M.
