How much water should you drink on Mounjaro?

If you're starting a weight loss journey with Mounjaro, it’s natural to ask: how much water should I drink each day, and does it even matter?

The short answer: yes, it sure does. Hydration is a key—but often overlooked—part of effective weight loss, especially when using medications that can impact your body’s fluid balance.

So, is there a magic number? Let’s explore how much water you really need on Mounjaro—and why keeping well-hydrated makes such a difference.

Why hydration matters while using weight loss medication

Whether you're on Mounjaro (tirzepatide) or Wegovy (semaglutide), staying hydrated is crucial not only for achieving your weight loss goals but also to help you feel your best throughout your journey.

Managing side effects

Weight loss injections can cause several side effects that lead to fluid loss and make you more vulnerable to dehydration, through symptoms like nausea and diarrhoea.

We'll dive deeper into this in just a bit, but in short, drinking water can help you replace lost fluids and manage side effects more comfortably. It also helps curb fatigue and improve digestion, both factors that help you stay consistent with your treatment.

Preventing bloating

Not drinking enough water can sometimes cause your body to hold onto fluids, leading to bloating or temporary weight gain, even as you lose fat. This effect can be made worse as your gut adjusts to the medication.

Keeping your hydration levels up helps stop your body from retaining extra water, so you feel less bloated and more comfortable.

Maintaining stable blood pressure

Dehydration can cause drops in blood pressure, resulting in dizziness or fatigue [1].

Drinking enough water supports healthy blood pressure levels and helps you feel more stable and energised while on your medication.

How much water to drink on Mounjaro

While individual needs vary, experts recommend drinking 2 to 3 litres of water per day while taking Mounjaro [2].

During dose escalations, it's wise to drink a little bit more, as your body adjusts to the medication and its side effects. The same applies on warmer days, when sweat increases fluid loss and dehydration risk.

If you're considering Mounjaro but want to make sure you're using it safely and effectively, Juniper can help.

Juniper's Weight Loss Reset Programme combines weight loss medication with dietitian-led health coaching and tracking, so you can lose weight and reach your goals for good.

Kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that mimic the GLP-1 and GIP hormones, respectively, to help control cravings, delay stomach emptying, and keep you feeling fuller for longer. These clinically backed treatments help members experience up to 20% body weight loss.

Plus, we have a team of expert dietitians and health coaches you can consult with to help you work through any challenges you're experiencing during your weight management journey. This approach sets you up for sustained weight loss, rather than a quick-fix solution.

This means you can continue to enjoy the things you love in moderation without ever feeling deprived.

Ready to see if Juniper is right for you? You can check your eligibility here.

Mounjaro and hydration

Now you know how much water you should be consuming while on Mounjaro, but what exactly is the link between hydration and the medication itself?

To answer this question, we need to understand how Mounjaro works.

In a nutshell, Mounjaro activates two hormones involved in blood sugar and appetite regulation—GIP and GLP-1—which work together to curb hunger, turn down cravings, and slow gastric emptying. This helps you feel fuller for longer and, as a result, supports weight loss.

But in doing so, Mounjaro can also impact the way your body processes fluids. Specifically, it can cause side effects like nausea, vomiting, diarrhoea, and constipation, all of which can increase fluid loss.

It's also not uncommon for patients on Mounjaro to feel thirstier than usual and experience dry mouth—a sensation often described as having cotton or cardboard in the mouth, or a sticky, dry feeling in the mouth and throat.

Drinking enough water can help ease these symptoms and make the medication more tolerable, especially during the early stages or dose adjustments. But how do you know if you’re getting enough?

Signs of dehydration to watch out for

Even mild dehydration can make you feel worse on medications like Mounjaro, not to mention, slow down your metabolism and hinder your weight loss progress.

And the thing is, dehydration can sneak up on you, especially if you're eating fewer calories than usual or losing fluids through the side effects we mentioned before.

So, it's important to watch out for common signs, including:

• Headaches
• Fatigue or light-headedness
• Dark yellow urine
• Dry mouth or lips
• Constipation
• Dizziness

It's easy to mistake these signs for Mounjaro side effects, but they could very well be your body’s way of telling you it needs more fluids.

The reality is that dehydration isn’t just uncomfortable—it can lead to more serious health issues, including kidney complications, so it’s important to stay on top of it. If you’re ever unsure or have concerns, speak with a healthcare professional.

The role of water in weight loss

When starting their weight loss journey, most people hear the same advice: eat a balanced diet and exercise regularly. And while those are two key pieces of the puzzle, water plays a bigger role in weight loss than we give it credit for.

In fact, it can help:

• Boost your metabolism. Drinking water increases energy expenditure (the number of calories your body burns at rest) and studies suggest it can boost your metabolism by up to 25% for an hour after drinking it [3].
• Suppress your appetite. Although it has zero calories, water is a great natural appetite suppressant. Several studies show that drinking water before meals can help you feel fuller and naturally reduce your calorie intake [4][5].
• Reduce cravings. Proper hydration can minimise cravings, helping you avoid poor food choices that could otherwise slow your progress. This can be especially helpful as you're getting used to a reduced food intake.
• Improve digestion. Water helps break down the food you eat, making sure your body is absorbing nutrients and protein effectively, which is key to losing fat and building muscle.
• Make it easier to exercise. Adequate hydration supports your energy levels, giving you fuel to exercise, burn calories, and, as a result, lose weight. It also improves circulation and helps your joints move freely, making it easier to stick with your exercise plan.

Tips for drinking more water

So, it's clear that drinking water can help your weight loss efforts in more ways than one, but we know it's often easier said than done. Let's be honest: how many of us have ever gotten to the end of the day and realised we only had one, maybe two glasses of water?

The good news is, there are simple habits you can adopt to help make hydration second nature:

• Carry a reusable water bottle with you throughout the day
• Set regular alarms on your phone, reminding you to take a sip
• Use a hydration tracking app to monitor how much you’ve drunk throughout the day—and how much more to go until you reach your goal
• Eat your water by incorporating hydrating whole foods like cucumber, watermelon, and oranges into your diet
• Try lemon water or herbal teas—perfect for when plain water sounds a little bit too boring
• Consider hydration tablets to replenish your electrolyte levels
• Pair your water intake with daily routines—for example, have a glass after brushing your teeth or between TV episodes
• Sip on protein water throughout the day (not only will it increase your water intake, but it will also help you hit your daily protein goals)

What about other medications like Wegovy?

Wegovy is different from Mounjaro in that it mimics one hormone in the body—GLP-1—rather than both GLP-1 and GIP.

Still, it comes with comparable side effects—including nausea, slowed digestion, and increased thirst—so the hydration advice we went over before also applies to Wegovy.

In fact, it applies to pretty much all weight loss medications.

So, whether you’re on Mounjaro, Wegovy or another drug, staying well-hydrated is one of the simplest (and most effective) ways to help you lose body weight without sacrificing your well-being.

When to speak to your health coach or healthcare provider

If you're struggling to stay hydrated, experiencing frequent nausea, or simply unsure how much water you need, it’s always smart to check in with a professional.

They can help by:

• Adjusting your hydration plan
• Recommending electrolyte support, if needed
• Advising you on how to manage side effects more comfortably
• Ruling out other causes if dehydration symptoms persist

Mounjaro and other weight loss medications can be a great help for your health, but they’re not for everyone.

In some cases, the side effects may outweigh the benefits, but with weight loss experts like Juniper by your side, you can get the support you need to find the approach that works best for you, and for how much weight you want to lose.

Frequently asked questions

Starting a weight loss journey with Mounjaro can bring up a lot of questions, especially when it comes to hydration. Staying properly hydrated is more than just a health tip. It’s a cornerstone of your success with weight loss injections.

Can I drink too much water on Mounjaro?

While staying hydrated is essential, excessive water intake can lead to a rare condition called hyponatremia, or low blood sodium. We recommend spreading your water intake evenly throughout the day and following your healthcare provider’s guidance.

Can I drink other fluids besides water while on Mounjaro?

Yes, definitely! We mentioned lemon water and herbal teas before, but there are other low-calorie, non-caffeinated drinks that can count toward your hydration goals, like cucumber-infused water and coconut water (in moderation). Just make sure to avoid sugary drinks, as they're full of empty calories that can hinder weight loss.

How does hydration affect exercise performance during weight loss?

When you're well hydrated, your body can regulate temperature more effectively, maintain energy levels, and support proper muscle function, all of which are essential for a good workout. Dehydration, on the other hand, can lead to fatigue, muscle cramps, and reduced endurance, making it harder to stick to your exercise routine. It can also slow your recovery after workouts, leaving you feeling sore and less motivated to stay active.

Are electrolyte drinks necessary while on Mounjaro?

There is a lot of talk at the moment about how electrolytes can help those using Mounjaro to stay hydrated. If you're experiencing side effects like nausea, vomiting or diarrhea, or if you're sweating a lot during exercise, you may be losing essential electrolytes such as sodium, potassium, and magnesium. In these cases, an electrolyte drink can help replenish what's lost and keep your body balanced.

Does protein water count towards my daily intake?

Yes, protein water can count toward your daily intake. Since it's primarily water with added protein, it helps keep you hydrated while also supporting your daily protein goals. Be sure to keep an eye on the ingredients, however, as some protein waters may contain added sugars or artificial ingredients that could impact your overall calorie intake. Balance is key, though, so be sure to also drink plain water throughout the day to ensure you're fully hydrated.

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