Does Mounjaro Make You Cold?

If you’re using Mounjaro, you’re probably experiencing some changes, including steady weight loss and a smaller appetite. But maybe you’ve also noticed that you’re colder than usual, particularly in your hands and feet.

It’s not just you. A lot of users have reported feeling a bit chillier than usual. But it’s not listed among the common side effects of Mounjaro.

So could Mounjaro be making you cold? Here, you’ll learn why it happens and how you can manage it.

Is Feeling Cold a Side Effect of Mounjaro?

Feeling cold isn’t listed as a side effect of Mounjaro (tirzepatide) on the medication’s patient information leaflet. But that doesn’t mean there isn’t a link between the two. 

While not listed among Mounjaro’s side effects, including nausea, constipation, and fatigue, many patients report feeling colder than usual. Especially in their hands and feet. So if this sounds familiar, you’re not alone. 

However, it’s possible that changes Mounjaro causes in your body – including a reduced appetite and weight loss – are leading you to feel cold. 

In most cases, feeling cold on Mounjaro is not dangerous. You should return to a comfortable temperature as your body adjusts to your treatment and changes in your lifestyle.

But it can be uncomfortable. If the cold is affecting your daily life, knowing why it’s happening and how to manage it can make weight loss easier.

Why Does Mounjaro Make You Cold?

There are a few reasons why you might feel colder while using Mounjaro. The medication itself is probably not the main cause of it. Instead, it’s more likely that weight loss and eating less on Mounjaro is causing your body temperature to drop.

Less Body Fat Means Less Insulation

Fat acts as insulation. The fat that sits just under the skin, known as subcutaneous fat, helps trap heat and protect your body from cold environments. 

As you lose fat through diet, exercise or medication like Mounjaro, you also lose some of that protective layer. Simply put, your body has less padding to keep warmth in. That can leave you feeling cold.

If you’ve lost weight rapidly, you may notice the temperature difference even more. Feeling cold could be a sign that you’re losing too much body weight, too quickly. Aim for steady weight loss of 1-2 lbs per week.

Reduced Food Intake

Calories in food give you energy to move and keep your body warm. When you consume fewer calories, your body produces less heat. 

Mounjaro works by mimicking two hormones that help regulate your appetite: glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP). This action suppresses your appetite, which means your food intake will likely decrease.

Feeling cold may be more noticeable when your intake drops significantly. This is usually during the first few weeks of using Mounjaro weight loss injections. While eating less is normal, make sure you’re not eating too little by planning regular meals made up of nutrient-dense whole foods.

Metabolism Slows During Weight Loss

As you lose weight, your metabolic rate may slow down. This means your body burns energy slower as a way to conserve fuel. Losing muscle mass, which can happen with weight loss, can also contribute to a slower metabolism.

This is a natural response to losing weight. But when your metabolism slows down, your body produces less heat. That can leave you feeling cold more often, especially when you’re resting.

Possible Nutrient Deficiencies

In some cases, weight loss or diet changes can impact how many nutrients you’re eating and how well your body absorbs them. This may impact body temperature.

If you’re low in iron or vitamin B12, you might feel colder than usual. These deficiencies can appear during periods of calorie restriction or if your diet becomes more limited. For example, if you’re skipping meals or cutting out food groups.

Your doctor can arrange a simple blood test to identify deficiencies and provide treatment, which should improve your symptoms. 

Eating a variety of nutritious whole foods is the best way to get enough nutrients. But you might want to consider adding a supplement, where you’re finding it hard to meet certain requirements.

Mounjaro Could Affect “Brown Fat”

Some research suggests that GLP-1 receptor agonists, like Mounjaro, might affect how your body uses a type of fat that keeps you warm. This fat, called brown fat or brown adipose tissue (BAT), burns calories to make heat (called thermogenesis). 

Because Mounjaro may impact BAT, the fat might not be doing its job as well. So you might feel colder than usual.

Scientists are still learning how these medications impact brown fat activity. But it’s another possible reason some people using Mounjaro may feel cold sensitivity.

Why Hands and Feet Get the Coldest

When you are cold, circulation to your hands, feet, ears and nose (your extremities) reduces.

This is because your body is designed to protect your vital organs, including the heart, lungs and brain. When it detects cold, it prioritises warming these essential areas over hands and feet.

Cold hands and feet can be even more noticeable if you’ve lost a lot of weight or are eating too little.

How Long Will I Feel Cold on Mounjaro?

It’s not clear how long you might feel cold on Mounjaro, since it’s not an official side effect. But it’s likely you’ll start feeling less cold once your weight levels out.

As your body adjusts to your weight loss, your metabolism should gradually pick up again. This will help your body generate heat, which will reduce cold sensitivity. Particularly if you’re no longer in a calorie deficit or actively losing fat.

For some, feeling cold may come and go depending on changes in diet, weight or even the weather. While it can be uncomfortable, it’s often part of your body adapting to new patterns. For many, it becomes more manageable with time and lifestyle changes.

How to Manage Feeling Cold on Mounjaro

You should start feeling less cold as your body weight stabilises. But if feeling cold is getting to you, here are some simple, effective ways to feel warmer and more comfortable:

• Layer Your Clothing: Dressing in layers is one of the best ways to trap heat. Try thin thermal layers under your clothes, warm socks, soft scarves and gloves. Hot water bottles or electric blankets can also provide relief at home or your desk.

• Eat Warming, Nutrient-Rich Foods: Choose nutritious meals that warm you from the inside out. Add lean protein to help you maintain muscle mass. Include healthy fats (like olive oil, nuts and avocado) to support hormonal balance and meet your nutritional needs.

• Stay Active: Light movement, even stretching, walking or household chores, can boost circulation and body heat. Even small increases in physical activity can help reduce the feeling of cold, especially in your hands and feet.

• Eat Small, Frequent Meals: Eating enough food and regularly will keep your metabolism gently engaged throughout the day. This helps you maintain body heat, especially if your calorie intake is on the lower side. It also prevents long gaps without food, which can cause your body to conserve energy and generate even less warmth.

• Drink Warm Fluids Regularly: Sip hot tea, broth, or warm lemon water throughout the day. This will not only hydrate you, but help raise your core temperature. It’s also a soothing way to stay relaxed and warm.

When to Talk to Your Doctor About Feeling Cold

If you’re on Mounjaro and feeling cold, you should feel warmer over time as your body adapts to weight changes. But, in some cases, it can be a sign of something more serious. 

Check in with your doctor if you notice:

• You’re cold all the time, regardless of the environment
• You have numbness, tingling or discolouration in your fingers or toes
• You’re experiencing fatigue, brain fog or mood swings
• You’ve lost weight rapidly or unintentionally
• You suspect a thyroid condition, anaemia or nutrient deficiency
  

Your doctor may recommend blood tests to check your iron and vitamin B12 levels. And they’ll assess your overall health. 

Feeling cold might indicate your weight loss has been too quick. If this is the case, your prescriber will evaluate your current Mounjaro dosage and make changes where appropriate.

If you are a patient with Simple and feel cold during your weight loss journey, our Patient Care team is here to help. Call us on 0141 774 5023.

Key Takeaways

• Feeling Cold on Mounjaro Isn’t uncommon: Feeling cold isn’t listed as a side effect. But many users have reported feeling colder than usual after starting Mounjaro. 

• Weight Loss and Eating Less Play a Role: Losing body fat and eating fewer calories can lower your internal heat production. This can make you feel cold more often. Your body has less insulation and fuel to burn for warmth, which can leave you more sensitive to cool temperatures.

• Hands and Feet Get Cold First: Your body naturally sends less blood to your extremities to keep your core warm and protect your vital organs. This is why your fingers, toes and nose can feel especially cold.

• Simple Habits Can Help You Stay Warm: Dress in layers, eat warm meals, stay active, swap cold drinks for warm ones, and use heating pads or blankets.

• Talk to Your Doctor If the Cold Feels Extreme: Constantly cold, experiencing numbness or suspect thyroid issues or nutrient issues? Check in with your healthcare provider. They can rule out underlying problems.

References

Package leaflet: Information for the patient (n.d.). Available at: https://www.medicines.org.uk/emc/files/pil.15481.pdf.

Churuangsuk, C., Griffiths, D., Lean, MEJ., Combet, E., 2019. Impacts of carbohydrate-restricted diets on micronutrient intakes and status: A systematic review. Obesity Reviews [online]. 20(8), pp. 1132-1147. Available from: https://pubmed.ncbi.nlm.nih.gov/31006978/

González-García, I., Milbank, E., Diéguez, C., López, M., Contreras, C., 2019. Glucagon, GLP-1 and Thermogenesis. International Journal of Molecular Sciences [online]. 20(14), pp. 3445. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6678955/.

Gornall, J., Villani, RG., 1996. Short-term changes in body composition and metabolism with severe dieting and resistance exercise. International Journal of Sport Nutrition and Exercise Metabolism [online]. 6(3), pp. 285-294. [Available from: https://pubmed.ncbi.nlm.nih.gov/8876348/

Soare, A., Cangemi R., Omodei, D., Holloszy, JO., Fontana, L., 2011. Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans. Aging [online]. 3(4), pp.374-379. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC3117452/

Zhang, M., Wang, L., Yang, J., Wang, F., Yang, J., Pan, W.,Xu, Y., 2023. Impact of body fat and fitness on human thermal responses under transient neutral-cool indoor conditions. Building and Environment [online]. 234. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0360132323002330

Authorship

Updated 24/06/2025