By Lalit Matai, GPhC Pharmacist Independent Prescriber at MediGlow Aesthetics & Health

Mounjaro (tirzepatide) is the most effective weight management medication currently available in the UK. In the SURMOUNT-1 trial, participants lost an average of 20.9% of body weight over 72 weeks — results that were previously only seen with bariatric surgery.¹ The interest is justified. But so is the caution.

Mounjaro is a prescription medicine, not a lifestyle shortcut. Used well, it can be genuinely transformative. Used without proper assessment, monitoring, or lifestyle change alongside it, it carries real risks — and the results rarely last. Here is what a responsible starting point looks like.

How it works

Tirzepatide is a dual GIP and GLP-1 receptor agonist. It activates two gut hormone pathways simultaneously, slowing gastric emptying, reducing appetite, and improving insulin sensitivity. The result is that most people eat significantly less without feeling deprived. What it does not do is determine what you lose, whether you retain muscle, or whether the weight stays off once you stop. Those outcomes depend on what you do alongside it.

The assessment: why it cannot be skipped

A proper clinical assessment is not a formality — it is what determines whether Mounjaro is safe for you specifically. This means a full medical history, medication review, blood pressure, BMI.

Mounjaro is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN2).² It requires careful clinical management in patients with a history of pancreatitis, gallbladder disease, diabetic retinopathy, or those taking insulin or other hypoglycaemic agents.

If a clinic is willing to prescribe after a short online form with no clinical review, that tells you something important. Weight management medication requires the same rigour as any other prescribing decision.

Risks and serious complications

Pancreatitis. GLP-1 receptor agonists have been associated with acute pancreatitis.³ Severe, persistent abdominal pain — especially pain radiating to the back — requires stopping the medication and seeking urgent medical attention.

Gallbladder disease. Rapid weight loss increases the risk of gallstones, and Mounjaro accelerates this further.´ Symptoms including upper right abdominal pain, nausea, and fever after fatty meals should be assessed promptly.

Thyroid. Animal studies identified thyroid C-cell tumour risk with tirzepatide — which is why a personal or family history of medullary thyroid carcinoma is an absolute contraindication.² Any unexplained neck lump or hoarseness during treatment should be reviewed.

Muscle loss. This is the most underestimated risk. Without adequate protein and resistance exercise, a significant proportion of weight lost can be lean muscle mass.µ Muscle loss at scale affects metabolism, bone density, physical function, and the likelihood of regaining weight when the medication stops.

Protein: the non-negotiable

Current evidence supports a minimum of 1.2 to 1.6 grams of protein per kilogram of body weight per day during active weight loss to preserve lean mass.⁶ For most patients, this requires a deliberate change in how meals are built. Protein comes first — eggs, chicken, fish, Greek yoghurt, lentils, cottage cheese. On days when appetite is very low (common after each dose increase), a quality protein supplement can help you hit your target without a full meal.

Patients who prioritise protein consistently throughout treatment finish in a fundamentally different physical condition to those who do not. The number on the scale may look similar. The body composition rarely is.

Exercise and lifestyle change

Resistance training two to three times per week — weights, bands, or bodyweight — is the most important form of exercise during Mounjaro treatment. It signals the body to retain muscle even in a caloric deficit and supports long-term metabolic health.⁷ Regular walking (8,000–10,000 steps daily) is consistently underrated and meaningfully supports cardiovascular and metabolic outcomes.

The data on weight regain after stopping tirzepatide is unambiguous: in the SURMOUNT-4 trial, participants who discontinued treatment regained approximately two thirds of their lost weight within one year.⁸ Mounjaro reduces the noise of hunger. It does not address the underlying behaviours, sleep, stress, or emotional eating patterns that contribute to weight in the first place.

The window the medication creates is only valuable if you use it to build habits that will exist independently of the injection. Patients who do that consistently achieve the best long-term outcomes.

How we work at MediGlow

We do not prescribe Mounjaro via an online form. Every patient has a full clinical consultation with a GPhC-registered pharmacist independent prescriber, including a medical and medication review, baseline measurements, and a frank conversation about what the treatment requires. We monitor regularly, adjust doses based on clinical response, and we are available if something does not feel right.

Mounjaro can be a powerful tool in the right clinical context. Our aim is for every patient who starts it to finish not just lighter, but healthier, stronger, and with the habits to stay that way.

To book a weight management consultation at MediGlow Aesthetics & Health , 1 Spiersbridge Way, Thornliebank, Glasgow, call 07383 895761 or visit medi-glow.co.uk.

Clinical References

  • Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205–216. doi:10.1056/NEJMoa2206038 (SURMOUNT-1 trial)
  • Eli Lilly and Company. Mounjaro (tirzepatide) Summary of Product Characteristics. European Medicines Agency. 2023.
  • Tkac I, et al. Pancreatitis and GLP-1 receptor agonists: a systematic review and meta-analysis. Diabetes Obes Metab. 2021;23(7):1619–1627.
  • Frossard JL, et al. Cholelithiasis risk and weight loss interventions including GLP-1 receptor agonists. Ther Adv Gastroenterol. 2023;16. doi:10.1177/17562848231156929
  • Wilding JPH, et al. Body composition changes with tirzepatide in SURMOUNT-1: lean mass considerations. Obesity. 2023;31(Suppl 1):Abstract presentation.
  • Stokes T, et al. Recent perspectives regarding the role of dietary protein for the promotion of muscle hypertrophy with resistance exercise training. Nutrients. 2018;10(2):180. doi:10.3390/nu10020180
  • Westcott WL. Resistance training is medicine: effects of strength training on health. Curr Sports Med Rep. 2012;11(4):209–216.
  • Aronne LJ, et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity (SURMOUNT-4). JAMA. 2024;331(1):38–48. doi:10.1001/jama.2023.24945