Mounjaro – A Hot Topic!
In recent years, Mounjaro (official name: tirzepatide) has emerged as one of the most talked-about medications in the weight loss world. With reports of significant weight loss results – seemingly easily – it’s gained attention from both medical professionals and individuals struggling with excess weight. However, as with any medicine it’s really important to understand what Mounjaro is, how it works, and—most importantly—how it fits into a comprehensive approach to health that includes exercise.
I have spoken to clients, friends and other personal trainers about this new weight loss drug and it seems to be on every other social media post. I want to explore the good, bad and most important info around Mounjaro for weight loss. I’ll try to be fair, objective and insightful…
What Exactly is Mounjaro?
Mounjaro is an injectable prescription medication manufactured by medicine creation company Eli Lilly. What makes Mounjaro unique is its dual-action mechanism—it functions as both a GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptor agonist. In terms we canactually understand, it mimics two natural hormones that regulate blood sugar, insulin secretion and appetite.
Mounjaro is administered once-weekly by subcutaneous injection (under the skin). It comes in a pre-filled self-injectable pen with various dosage options, ranging from 2.5mg (the lowest or starter dose) to a maximum dose of 15mg. The medication is typically started at a low dose and gradually increased over time to minimise the side effects.
Where Did Mounjaro Come From?
Mounjaro’s journey to becoming a weight loss medication was somewhat unexpected. Eli Lilly initially developed tirzepatide as a treatment for type 2 diabetes, focusing on its ability to improve glycaemic control. In December 2022, Mounjaro received approval from the Medicines and Healthcare products Regulatory Agency (MHRA) for treatment of type 2 diabetes in the UK, following earlier approvals in the US and EU.
However, researchers noticed something remarkable during the diabetes trials—participants were losing significant amounts of weight. This “side effect” prompted further investigation into tirzepatide’s potential as a dedicated weight management medication. This led to the ‘SURMOUNT’ clinical trial programme, which specifically studied the drug’s effects on weight in people with obesity, with or without diabetes.
What is Mounjaro Used For?
In the UK, Mounjaro is currently approved by the MHRA for:
– Treatment of type 2 diabetes mellitus in adults
While the European Medicines Agency (EMA) has approved tirzepatide for weight management under the brand name Mounjaro (unlike in the US where it’s marketed as Zepbound for this purpose), the NHS does not routinely fund it specifically for weight loss at present. Access for weight management through the NHS is currently limited, though this may change as guidelines evolve.
Some patients may access it through private healthcare providers specifically for weight management, while others may receive it on the NHS for diabetes with weight loss as a beneficial additional effect.
Is Mounjaro Good for Weight Loss?
The clinical evidence regarding Mounjaro’s effectiveness for weight loss is compelling . In the ‘SURMOUNT-1 trial’, participants taking the highest dose of tirzepatide (15mg) lost an average of 22.5% of their initial body weight over 72 weeks (17 months)—approximately 23.6kg / 3st 10lb for someone weighing 104kg / 16st 5lb. Even at lower doses, the results were significant, with the 5mg dose yielding about 16% weight loss.
These results exceed what has been typically seen with older GLP-1 medications like Ozempic/Wegovy (semaglutide), which showed average weight loss of about 15% in its clinical trials.
However, it’s important to understand that:
- Some weight regain occurs if the medication is discontinued
- Individual results vary considerably depending on how the individual
- Weight loss tends to plateau after about a year based on user’s experience
- The medication works best when combined with dietary changes and exercise – maintaining these changes after stopping Mounjaro decrease the likelihood of regaining weight
Should I Use Mounjaro?
Deciding whether Mounjaro is right for you involves several important considerations:
Medical supervision: Mounjaro is a prescription-only medicine that requires ongoing medical supervision. It is not appropriate as a casual or short-term solution for cosmetic weight loss. Buying it online comes with risks you will not receive a genuine Mounjaro product, which heightens the risks further.
Appropriate candidates: In general, when prescribed for weight management (typically through private healthcare in the UK currently), Mounjaro would be considered for adults with:
- A BMI of 30 or greater (obese category), or
- A BMI of 27 or greater (overweight category) with at least one weight-related condition such as hypertension, type 2 diabetes, or dyslipidaemia
- For British Asian, Black, and other minority ethnic groups, lower BMI thresholds may apply (typically 2-3 points lower)
Cost and accessibility: Through private healthcare, the medication costs approximately £150-£200 per month in the UK. On the NHS, it is primarily accessible to those with type 2 diabetes who meet specific criteria, though this varies by regional NHS trust.
Commitment to lifestyle changes: Mounjaro works best when viewed as one component of a comprehensive approach that includes dietary changes and regular physical activity, particularly strength training.
Risks and Benefits
Benefits:
- Significant and clinically meaningful weight loss
- Improvements in cardiovascular risk factors including blood pressure and cholesterol levels
- Better glycaemic control for those with diabetes or prediabetes
- Potential improvements in obesity-related conditions like sleep apnoea, PCOS, and joint pain
- Improved quality of life and mobility for many users
Risks:
- Common side effects include nausea, vomiting, diarrhoea, constipation, and abdominal pain
- Less common but serious side effects may include pancreatitis, gallbladder problems, and hypoglycaemia
- There is a warning about thyroid C-cell tumours observed in animal studies (though human relevance is unknown)
- Potential for muscle loss if not combined with adequate protein consumption and resistance exercise (weight training)
- Long-term effects beyond several years are still being studied
Exercising on Mounjaro: Why Weight Training Matters
While Mounjaro can be effective for weight loss on its own, incorporating exercise—particularly resistance training—is crucial for the best results.
Preventing muscle loss: When losing weight rapidly, the body often breaks down both fat and muscle tissue. Studies suggest that up to 25% of weight lost during caloric restriction can come from lean muscle mass. This is concerning because muscle:
- Determines functional strength and mobility
- Contributes to a higher resting metabolic rate
- Helps maintain insulin sensitivity
- Supports bone health and prevents osteoporosis
Resistance training recommendations: For those using Mounjaro, consider:
- Starting with 2-3 full-body strength sessions per week
- Focusing on compound movements like squats, deadlifts, rows, and chest presses
- Beginning with light weights and proper form before progressing
- Working with a personal trainer initially if new to resistance training
Protein considerations: Mounjaro users often experience decreased appetite, which can make adequate protein consumption challenging. Aim for:
- At least 1.6-2.0 grams of protein per kilogram of ideal body weight
- Distribute protein throughout the day (20-30g per meal)
- Consideration of protein supplements if it’s difficult to get protein goals from food
Cardiovascular exercise: While strength training should be prioritised, moderate cardiovascular exercise offers additional benefits:
- Improved cardiovascular health and endurance
- Enhanced mood and stress reduction
- Additional calorie expenditure
A balanced approach that includes 150 minutes of moderate aerobic activity weekly alongside 2-3 strength training sessions appears optimal for most Mounjaro users, aligning with current NHS physical activity guidelines.
Summary
My personal take is this: it definitely works. There is no denying the media coverage, which reports everything from success stories to supermarkets and fast food businesses complaining about declining food sales since Mounjaro’s release. I have followed the rise in popularity of the drug and understand the appeal – it’s a quick fix for a problem so many of us experience… it’s bloody hard to lose weight!
If a client, friend – or anyone – sought my advice I would ask them to consider exhausting all other means first – diet and exercise are the basis of weight loss. If there is no other option then sure, proceed… but with caution. This drug is new, it was never intended specifically for losing weight and, like any medication, comes with side effects.
Mounjaro represents an important advancement in medical weight loss solutions, offering significant results for many people. It definitely works best as part of a comprehensive approach to health rather than a standalone solution.
Weight management is a complex, ongoing journey rather than a destination. When used properly and combined with exercise and good diet, medications like Mounjaro can be valuable tools in improving health for those of us struggling with obesity and related conditions.
Note: This article is for informational purposes only and does not constitute medical advice. Please consult with your GP or healthcare provider before starting any new medication or exercise programme.
