Two GLP-1 weight-loss injections are now licensed in the UK: Mounjaro (tirzepatide) and Wegovy (semaglutide). Both are approved by the MHRA and available on the NHS through specialist Tier 3 weight management services — but access is severely rationed and waiting times can stretch 12 to 24 months. Most UK patients who want prompt access pay privately, where a month’s supply runs from approximately £119 to £340 depending on dose and provider.
SunnyPharma built this guide from NHS England commissioning documents, NICE Technology Appraisals TA1026 (tirzepatide) and TA875 (semaglutide), SURMOUNT and STEP trial data, and the GPhC regulatory framework. It covers what these medications do, what they cost in the UK, how the NHS pathway works, and where to find further information on each topic. For decisions about your own treatment, your prescribing clinician is the right source of guidance.
- Two licensed options: Mounjaro (tirzepatide, Eli Lilly) and Wegovy (semaglutide, Novo Nordisk)
- NHS access is limited: Tier 3 specialist services only — GPs cannot prescribe for weight management
- Private cost: £119–£340/month depending on dose and provider
- GPhC registration is mandatory for any online pharmacy dispensing Mounjaro or Wegovy
- Counterfeit risk is real: the MHRA has seized fake Mounjaro pens in the UK — only buy from GPhC-verified sources
- SURMOUNT-1 trial: tirzepatide 15 mg produced average 20.9% weight reduction over 72 weeks
What GLP-1 Weight-Loss Injections Do
GLP-1 receptor agonists mimic gut hormones that regulate appetite and blood sugar. After an injection, they slow gastric emptying, reduce hunger signals, and increase feelings of fullness — leading to a sustained reduction in calorie intake. Mounjaro also activates GIP receptors, making it a dual agonist; this additional mechanism is thought to contribute to its greater average weight loss versus semaglutide alone.
What GLP-1 Treatment Costs — and What Patients Actually Pay
Private GLP-1 treatment in the UK is paid entirely out of pocket — there are no equivalent assistance programmes to the US manufacturer PAP routes. The cost varies by medication, dose, and provider.
Why prices vary between UK providers
Every GPhC-registered pharmacy sources the same Eli Lilly-manufactured tirzepatide product. Price differences reflect clinical model, bundled services, and scale. Check what is included before comparing headline prices.
Affiliate disclosure: Some provider links in our individual guides may earn SunnyPharma a commission if you purchase through them. This never influences our editorial content or rankings. SunnyPharma does not prescribe or sell medications. We are an independent health education publisher.
NHS Access: What NICE Approval Actually Means for Most Patients
Both Mounjaro and Wegovy are NICE-approved for NHS prescribing — but approval does not mean your GP can write a prescription. NICE restricts both medicines to NHS specialist Tier 3 weight management services only.
- Eligibility criteria: BMI of 35 or above (or 30 or above with at least one weight-related comorbidity)
- Prior requirement: completion of an intensive, multi-component lifestyle intervention
- Route: GP referral to a Tier 3 specialist weight management service — GPs cannot prescribe directly
- Waiting time: 12 to 24 months in high-demand areas; NHS England is expanding capacity with broader rollout expected from 2026 onward
UK GLP-1 Guides
This hub links to in-depth guides on specific GLP-1 topics for UK patients. The first guide is live now; more are in production.
Frequently Asked Questions
Mounjaro costs between approximately £119 and £340 per month from GPhC-registered UK pharmacies, depending on dose and provider. The 2.5 mg starting dose ranges from £119 to £219; the 15 mg maximum dose from £209 to £340. Prices were checked in June 2026 and change frequently — always confirm directly with the provider before ordering.
Yes, but access is tightly rationed. NICE approved tirzepatide (Mounjaro) in December 2023 and semaglutide (Wegovy) in March 2023, both through specialist Tier 3 weight management services only. GPs cannot prescribe either drug directly. Eligibility requires BMI of 35 or above, completion of an intensive lifestyle programme, and a Tier 3 referral. Waiting times reach 12 to 24 months in many NHS trusts.
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) is a GLP-1 receptor agonist only. Both are licensed weekly injections for chronic weight management in the UK. Tirzepatide produces greater average weight loss in trials — approximately 20.9% at 15 mg over 72 weeks versus approximately 14.9% for semaglutide. Wegovy is generally less expensive.
Most patients notice reduced appetite within one to two weeks. Meaningful weight loss typically appears by weeks 8 to 12. The SURMOUNT-1 trial found patients on tirzepatide 15 mg lost an average of 20.9% of body weight over 72 weeks.
Mounjaro can be prescribed online by GPhC-registered UK pharmacies following a clinical assessment. Always verify a provider’s GPhC registration number at pharmacyregulation.org before purchasing. The MHRA has warned of counterfeit Mounjaro pens in the UK containing unknown substances.
No. Wegovy is generally less expensive, with starting costs from approximately £99 per month versus approximately £119 for Mounjaro. However tirzepatide produces greater average weight loss in trials, which may affect overall cost-effectiveness over a full treatment course.
The golden dose is an informal term for the Mounjaro dose at which a patient achieves their target weight-loss rate with tolerable side effects. Mounjaro is available in six strengths from 2.5 mg to 15 mg. The right maintenance dose is determined with a prescribing clinician based on individual response and tolerability.
Mounjaro face refers to facial volume loss during rapid weight loss on GLP-1 medications. It is a consequence of overall fat reduction, not a direct drug effect on facial tissue. Slower dose escalation and adequate protein intake may help minimise the effect.
How we reviewed this article:
SunnyPharma follows strict sourcing guidelines and relies on peer-reviewed studies, government agencies (MHRA, NHS England, NICE), and medical associations. Dr. Swiggum’s review covers the clinical content; cost figures are cross-checked against GPhC-registered UK provider pricing. We use only credible, verifiable sources to ensure accuracy.
Sources & References
- NICE Technology Appraisal TA1026 — Tirzepatide for managing overweight and obesity (December 2023): nice.org.uk
- NICE Technology Appraisal TA875 — Semaglutide for managing overweight and obesity (March 2023): nice.org.uk
- Jastreboff et al. — SURMOUNT-1: Tirzepatide once weekly for treatment of obesity. NEJM 2022: nejm.org
- Wilding et al. — STEP 1: Once-weekly semaglutide in adults with overweight or obesity. NEJM 2021: nejm.org
- MHRA — Medicines and Healthcare products Regulatory Agency: gov.uk/mhra
- NHS England — Tier 3 weight management services commissioning: england.nhs.uk
- General Pharmaceutical Council — Online pharmacy register: pharmacyregulation.org
- Eli Lilly — Mounjaro UK Summary of Product Characteristics: medicines.org.uk
- NHS — Treatment: Obesity: nhs.uk