What Is a GLP-1 Plan? A UK Guide (October 2026)

01 · The core answer

What a GLP-1 weight loss plan includes

A proper GLP-1 weight loss plan has four parts: the medicine, what you eat, how you move, and who reviews you. Mounjaro (tirzepatide) is a once-weekly injection licensed in the UK for weight management in adults. It is used alongside a reduced-calorie diet and increased physical activity.¹

The medicine does the appetite work. It activates GIP and GLP-1 receptors, which helps regulate appetite and slows how quickly the stomach empties. Most people feel fuller sooner and less hungry between meals, which makes a reduced-calorie diet easier to follow.¹ The diet, movement and reviews are what turn that into a plan.

02 · Your next step

Is a GLP-1 plan right for you?

It depends on your health and goals, so a prescriber has to decide. Our free online consultation is reviewed by a GPhC-registered prescriber, and unsuitable orders are refunded automatically. If you are ready to look at costs, the Mounjaro pen starts at £169.99 for the 2.5mg starting dose, with prices checked 12 October 2026. You can also read our wider weight loss clinic guide.

03 · Food and menu planning

GLP-1 nutrition plan and menu: what to eat

No food is banned on Mounjaro, including bananas. Some choices make treatment easier: prioritise protein at each meal, vegetables and fibre, and regular fluids. Many people feel worse after very fatty, fried or very sugary food. Large portions sit heavily because the stomach empties more slowly, so smaller, slower meals work better.

For worked examples, see our GLP-1 meal plan, the eating plan guide and the Mounjaro menu plan. Coffee and tea are fine, but high-calorie coffee drinks are an easy place for the deficit to leak.

04 · Exercise and muscle

GLP-1 workout and exercise plan

Increased physical activity is part of the licence, not an optional extra. Nothing special is required: regular moderate activity such as brisk walking, plus resistance work for muscle. Start where you are and build. On injection days with early side effects, lighter movement still counts.

Some of any rapid weight loss comes from lean tissue, and protecting muscle protects your metabolism, strength and appearance. The two levers are adequate protein at every meal and resistance exercise two or more times a week. This matters more, not less, as the dose rises and appetite falls. Exercise also protects against regain if you later stop treatment.

05 · Boosters and detox plans

GLP-1 boost, detox and supplement plans

Supplements sold as "natural GLP-1 boosters" are not equivalents and are not substitutes for prescribed treatment. No supplement is required with Mounjaro, but eating much less can leave gaps, so a standard daily multivitamin is a reasonable safety net while losing weight. Discuss anything beyond that with a pharmacist.

06 · Results and pace

What results to expect

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone. These are trial averages, and individual results vary.²

Early progress is slower. A sensible 3-month expectation on a standard titration is mid single digits as a percentage of body weight, with wide individual variation. See our 3 month plan and 6 month plan for how this builds. Plateaus of a few weeks are normal; review portions, protect protein and activity, and ask your prescriber about the dose.

07 · Maintenance and stopping

GLP-1 maintenance plan: planning the long term

Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average.¹⁴

Our payment plan guide covers spreading the cost.

08 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹