Why does Mounjaro make you cold?

Have you noticed yourself reaching for an extra jumper or turning up the heating since starting Mounjaro? If you're feeling colder than usual, you might be wondering whether your weight loss medication is responsible.

Although feeling cold isn't a commonly recognised side effect of Mounjaro, some people may notice this during treatment. Research suggests that calorie restriction can affect body temperature, while changes in body weight may also influence how you experience the cold.

In this guide, we'll explore why you might feel cold while taking Mounjaro, what could be contributing to the change, and some simple ways to stay comfortable as you continue your weight loss journey.

Can Mounjaro make you feel cold?

Yes, you might notice yourself feeling colder than usual while taking Mounjaro. However, feeling cold isn't listed as a common side effect in the official prescribing information, and there's currently limited evidence that the medication directly causes cold sensitivity.

Instead, feeling cold on Mounjaro may be linked to changes that happen during weight loss, such as eating fewer calories or losing body fat. Both can influence how your body produces and retains heat.

This means that feeling colder during treatment doesn't necessarily indicate a problem with the medication. However, persistent or unexplained cold sensitivity shouldn't automatically be attributed to Mounjaro, as other health conditions can also affect how your body responds to temperature.

Why does Mounjaro cause cold sensitivity?

There isn't one established explanation for why some people feel colder while taking Mounjaro. However, several changes associated with weight loss could contribute to increased cold sensitivity.

Losing body fat

Body fat helps insulate your body and reduce heat loss. As you lose weight on Mounjaro, a reduction in body fat may make you more sensitive to colder temperatures, particularly if you've lost a substantial amount of weight.

Eating fewer calories

Your body uses energy from food to support essential functions, including maintaining body temperature. Because Mounjaro reduces appetite, you might find yourself eating considerably less than before.

Research has found that long-term calorie restriction can lower core body temperature. Although this research wasn't specific to Mounjaro, it suggests that reduced energy intake could help explain why you feel colder during treatment.

Changes in metabolism

As you lose weight, your body generally needs less energy to maintain its functions. Research into the metabolic effects of weight loss also describes how energy expenditure can decrease beyond what would be expected from changes in body size alone.

These adaptations may influence heat production, although it's not clear how much they contribute to feeling cold on Mounjaro.

Changes in circulation

Your hands and feet may feel particularly cold because your body naturally reduces blood flow to the skin and extremities when temperatures drop. This helps conserve heat around your vital organs.

Cold hands or feet aren't necessarily caused by Mounjaro. However, if you're noticing unusually cold feet during treatment, particularly alongside pain, numbness, or changes in skin colour, speak to your healthcare team.

How to manage cold sensitivity while on Mounjaro

If you're feeling cold on Mounjaro, a few simple changes to your daily routine may help you stay more comfortable.

“Feeling colder than usual can be frustrating, especially when you're not sure what's causing it. Changes in your weight or how much you're eating could be contributing, so pay attention to when it happens. Eating regular meals, dressing warmly, and keeping active are all simple things that may help.”

Ayesha BashirPrescribing Pharmacist

• Dress in layers: Wearing several lighter layers can help trap warmth and make it easier to adjust your clothing as temperatures change. Warm socks and slippers may be particularly helpful if you're experiencing cold feet.
• Eat regular, balanced meals: Even if Mounjaro reduces your appetite, it's important to get enough energy and nutrients. Try eating smaller meals more frequently if you're struggling with larger portions.
• Keep moving: Gentle activities such as walking or stretching can help you warm up and stay active throughout the day. If you spend long periods sitting, try getting up and moving around regularly.
• Warm up gradually: A warm drink, extra blanket, or comfortable room temperature can help when you're feeling chilly. Avoid placing very hot objects directly against your skin, particularly if you have reduced sensation in your hands or feet.
• Monitor your symptoms: Pay attention to when you feel cold and whether it coincides with changes in your eating habits, weight, or activity levels. This information may help your healthcare team identify possible causes.

You don't need to stop taking Mounjaro simply because you're feeling colder than usual. However, if the discomfort persists or begins affecting your everyday life, speak to your pharmacist or healthcare team rather than changing your treatment yourself.

When to seek medical support

Feeling colder than usual while taking Mounjaro isn't necessarily a cause for concern. However, if you're constantly cold, your symptoms are getting worse, or they're affecting your everyday life, it's worth speaking to your pharmacist or healthcare team.

Cold sensitivity can sometimes be linked to other health conditions. For example, an underactive thyroid can cause increased sensitivity to cold, alongside symptoms such as tiredness, constipation, and dry skin.

If you're experiencing trembling, sweating, dizziness, or confusion, these could be signs of low blood sugar. This is particularly important if you're taking Mounjaro alongside insulin or certain diabetes medications, which can increase the risk of hypoglycaemia. Seek prompt medical advice and get emergency help if someone becomes unconscious or has a seizure.

Your healthcare team can help determine whether your symptoms are related to treatment, weight loss, or another underlying cause.

Getting support throughout your treatment

Feeling cold on Mounjaro can be uncomfortable, particularly when it's affecting your everyday routine. If you're concerned about changes in how your body responds to temperature, you don't have to manage them alone.

At myBMI, our treatment plans include ongoing clinical support to help you manage your weight loss safely and sustainably. Our clinical team can offer guidance on treatment-related concerns, including changes in appetite, nutrition, and potential side effects. When considered appropriate, we also provide free medication to help manage certain side effects.

For more information about what to expect during treatment, explore our guide to Mounjaro side effects.

With the right support, you can continue working towards your weight loss goals while looking after your comfort and long-term health.

Sources

• Mounjaro - Product information. (2026) European Medicines Agency. [Accessed 11 October 2026]
• Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans. (2011) Aging. [Accessed 11 October 2026]
• Metabolic Consequences of Weight Reduction. (2026) StatPearls. [Accessed 11 October 2026]
• Responses of the hands and feet to cold exposure. (2015) European Journal of Applied Physiology. [Accessed 11 October 2026]
• Hypoglycaemia (Hypos) - type 2 diabetes. (2024) HSE. [Accessed 11 October 2026]
• Underactive thyroid (hypothyroidism) symptoms. (2026) HSE. [Accessed 11 October 2026]