Why Won't My GP Prescribe Mounjaro? (October 2026)

01 · The reasons

The main reasons your GP says no

The first reason is the rollout stage. Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition. The primary-care rollout began in June 2025 with the highest-need groups first, initially BMI 40+ with four or more qualifying conditions.⁴⁶

So someone with a BMI of 27 and, for example, high blood pressure falls within the licence. They would not yet be within the NHS rollout. Read our guides on whether a GP can prescribe Mounjaro and whether your GP will prescribe it for weight loss.

02 · Other blockers

Other reasons a GP might decline

Your practice may not yet be offering the service locally, as availability differs by area. Your GP may also judge that your medical history or current medicines make it unsuitable, which is a prescriber's decision. If you have type 2 diabetes, see Mounjaro prescribing for diabetes. For wider options, see whether your GP can prescribe GLP-1 medicines. GPs can generally decline to prescribe a medicine they judge inappropriate or outside local commissioning; ask them to explain the reason and note it down.

03 · Next steps

What you can do next

Ask your GP which criteria you miss and whether local services are open yet, and ask to be reviewed as rollout widens. If you meet the licensed criteria and don't want to wait, regulated private treatment is an option. A free consultation is reviewed by a GPhC-registered prescriber, and unsuitable orders are refunded automatically.

The Mounjaro pen starts with a 2.5mg first pen at £129.99 on a first order with code FIRST40 (standard price £169.99), and all six doses are in stock. Every later order is £25 off the standard price. Delivery is free and next-day, with same-day dispatch when ordered by 3pm. See how to buy Mounjaro. Prices checked 10 October 2026.

04 · What Mounjaro does

What Mounjaro is and how it works

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes.¹

Tirzepatide activates two natural gut-hormone receptors at once, GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties and improve the way the body responds to insulin. Most people feel fuller sooner and less hungry between meals.¹

05 · What results look like

How quickly does it work, and what to expect

In SURMOUNT-1, which included 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone. Individual results vary. For someone starting at 100 kg, 20.9% is about 21 kg.²

These are trial averages, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.