Lost 7st on Mounjaro: Cold Side Effect Costs £70/Month

Emilly Murray's Dramatic Weight Loss on Mounjaro

Emilly Murray, a 35-year-old mum-of-three from Aintree, Liverpool, achieved a remarkable transformation with Mounjaro. Starting at 16 stone and a size 22, she dropped to nine stone and a size 6-8 in less than a year. This GLP-1/GIP receptor agonist, known generically as tirzepatide, helped her overcome persistent 'food noise' that had plagued her dieting efforts. Previously, she'd lost weight on her own to reach 16 stone but struggled with constant cravings. Mounjaro changed that within hours of her first dose, putting her in charge of her eating habits.

Mounjaro works by mimicking hormones that regulate blood sugar, slow gastric emptying, and reduce appetite, leading to significant calorie deficits and fat loss. For patients like Emilly, who purchase it privately at £200 per month for the 7.5mg dose, the results are profound—but not without challenges. Her total monthly cost, including an extra £70 on heating, hits £270 every four weeks. Yet, she insists it's "worth every penny," enabling her to run after her kids and climb stairs without breathlessness.

The Chilling Side Effect: 'MJ Freeze' and Rising Heating Bills

One unexpected Mounjaro side effect has Emilly "spending her life freezing." Known on TikTok as "MJ Freeze," this heightened cold sensitivity affects hundreds of weight loss jab users during winter. She noticed it after her first jab, shivering in bed with a hoodie on. This winter, she hasn't felt her toes or fingers once, describing it as an unnatural chill that worsens with water intake—crucial for staying hydrated on these medications.

To cope, Emilly keeps her heating at 22 degrees for over six hours daily, wears multiple layers including dressing gowns at home, and uses heated blankets, gloves, slippers, and a hot water bottle. Her energy bill skyrocketed from £85 to £155 monthly, a £70 increase directly tied to combating the cold. Daily tasks suffer too: school runs require thermals under pants, two t-shirts, a jumper, big coat, and gloves—yet she still freezes "to her core."

"It is absolutely horrendous... I love being seven stone lighter - but it has come with an unwanted side effect."

— Emilly Murray

Emilly attributes "MJ Freeze" to the massive calorie deficit from her 7st loss. "Our bodies are used to eating high amounts—so your body has a lot less energy to burn for heat," she explains. "I have not met a single person on Mounjaro who hasn't had MJ Freeze."

Why Does Mounjaro Cause Feeling Cold? Understanding the Mechanism

While Emilly links it to reduced calorie intake, dietitian Sioned Quirke, specializing in weight management, offers a nuanced view. "There is no robust clinical trial evidence that GLP-1 drugs directly cause people to feel cold as a pharmacological side effect," she states. Instead, it's tied to adaptive thermogenesis post-weight loss.

• Reduced subcutaneous fat: Fat acts as insulation; rapid loss via Mounjaro exposes the body to cold more easily.
• Lower caloric intake: Diet-induced thermogenesis drops, as does resting energy expenditure.
• Metabolic slowing: The body conserves energy, reducing heat production.

These changes are common with any significant weight loss, amplified by Mounjaro's potent appetite suppression. Compared to alternatives like semaglutide (Ozempic or Wegovy), tirzepatide's dual GLP-1/GIP action may accelerate fat loss, potentially intensifying insulation loss. Patients on GLP-1 therapies should monitor for this, especially in colder climates like the UK.

Emilly's Diet Transformation: Before and After Mounjaro

Mounjaro silenced Emilly's food noise, reshaping her eating habits for sustainability.

Diet Before Mounjaro

• Breakfast: Nothing
• Lunch: Sandwich, crisps
• Dinner: Takeaways, freezer food
• Snacks: Sweets, crisps, chocolate
• Drinks: Fizzy drinks

Diet After Mounjaro

• Breakfast: Protein shake and protein coffee
• Lunch: Chicken thighs, tuna bagels
• Dinner: Normal meals like curry, chicken, fried rice, healthy burrito bowls
• Snacks: Fruit, cheese, meat
• Drinks: 2-3L sugar-free juice

This shift supports muscle preservation and steady energy, countering some cold sensitivity by prioritizing protein. Hydration remains key, though cold water exacerbates chills—opt for room-temperature drinks.

Managing Cold Sensitivity on Mounjaro: Practical Tips for Patients

For those experiencing MJ Freeze, preparation is essential. Emilly advises layering strategically and investing in heated accessories. Other strategies include:

• Boost calorie-dense healthy fats: Avocados, nuts to aid thermogenesis without derailing weight loss.
• Exercise for heat generation: Light activity increases blood flow and metabolism.
• Supplements: Discuss omega-3s or iron with your doctor, as deficiencies can worsen cold intolerance.
• Track symptoms: Apps like Shotlee can log side effects, hydration, and heating use alongside your Mounjaro schedule for better doctor discussions.

Consult your healthcare provider before starting Mounjaro, especially if you live in cold regions. Common side effects like nausea are better studied, but cold sensitivity warrants monitoring. Private dosing like Emilly's 7.5mg requires oversight to avoid under-dosing or escalation.

Comparisons: Mounjaro vs. Other Weight Loss Injections

Mounjaro stands out for superior weight loss (up to 20% body weight in trials) versus semaglutide's 15%, but side effects like cold may scale with rapidity. Unlike pure GLP-1s, its GIP component enhances insulin sensitivity, potentially aiding metabolic recovery long-term. Patients switching from Ozempic report similar chills, but Mounjaro users note it more acutely due to faster results.

Is the Cold Worth It? Emilly's Verdict

Despite UK's harsh winters and at her heaviest over 22st, Emilly refuses to stop. "It's worth going through this cold—you just need to be prepared to get higher heating bills," she says. The freedom from food obsession outweighs the freeze.

Key Takeaways: What This Means for Mounjaro Patients

• Mounjaro delivers rapid weight loss (e.g., 7st in <1 year) but can trigger 'MJ Freeze' via adaptive thermogenesis.
• Expect higher energy costs (£70+/month for some); budget and layer up.
• Not a direct drug effect—linked to fat loss and calorie reduction.
• Prioritize protein-rich diets, hydration, and symptom tracking.
• Discuss with doctors: Ideal for those with obesity-related issues, but prepare for metabolic shifts.

Final Thoughts: Emilly's story highlights Mounjaro's transformative power alongside real-world challenges. For sustainable success, combine it with lifestyle tweaks and professional guidance. If considering tirzepatide, weigh the chills against life-changing benefits.