Think your Mounjaro pen has stopped working? The issue likely isn’t with the medication. Here’s what could really be going on.
One of the most common concerns we hear from patients using Mounjaro (or other GLP-1 medications) goes something like this:
“Since increasing my dose of Mounjaro, I’ve had zero appetite suppression, and my food noise is back full force. Is there a problem with the batch? I didn’t feel hungry at all on my last dose and hardly ate anything. Now I can’t stop eating!”
If this sounds familiar, you’re not alone - and the issue likely isn’t with your medication. This experience can be frustrating but understanding what’s happening helps you respond in a way that supports your long-term success.
Why am I hungry again when taking Mounjaro?
This type of reaction often happens after a dose increase, especially during the early stages of treatment. Patients typically enter a “honeymoon phase” with GLP-1 medications like Mounjaro. During this time, appetite is significantly suppressed, cravings diminish, and food intake drops - often dramatically.
But after a few weeks, something changes. In a natural effort to restore balance, the body pushes back. Hunger signals and cravings return—sometimes stronger than before. This frequently aligns with a dose increase, leading many to believe that the medication has stopped working or that there’s a problem with the batch.
Want to explore this in more detail? Read our blog on why you might still feel hungry on Mounjaro.
It’s Not the Medication - It’s Your Body Responding
In most cases, this isn’t due to a bad batch or an ineffective dose.
What’s actually happening is a biological response to undereating. When calorie or protein intake drops too low (which can easily happen when your appetite is suppressed), the body senses an energy deficit and fights back to correct it.
This “pushback” is your body's built-in survival mechanism. It increases hunger and intensifies “food noise” in an attempt to get you to eat more, because it’s trying to protect you from what it perceives as starvation.
How to Support Healthy, Sustainable Weight Loss on Mounjaro
Success with GLP-1 medications isn’t just about taking the medication, it’s about fuelling your body appropriately so it can function well and lose weight sustainably. Here’s what we recommend:
1. Minimum Daily Calorie Intake Guidelines
These calorie ranges are absolute minimums - not targets. Consistently eating below these levels can trigger intense hunger, fatigue, and metabolic slowdown.
To support healthy, steady weight loss, aim for a moderate calorie deficit of around 500 calories per day below your maintenance needs. This typically results in about one pound of fat loss per week which is an effective and sustainable rate.
- Women: Minimum of 1,200-1,500 calories per day
- Men: Minimum of 1,500-1,800 calories per day
Keep in mind: many patients need to eat more than these minimums, depending on body size, activity level, and overall health. Chronically undereating can stall weight loss and increase hunger, even when on medication.
2. Minimum Daily Protein Intake Guidelines
Protein is crucial during weight loss. It helps preserve lean muscle mass, supports metabolism, and promotes satiety.
We recommend the following minimum protein intake:
- 60-75 grams per day for most individuals
- Higher intake if your BMI is over 40 kg/m² or if you’re very physically active
If you don’t get enough protein, your body may increase hunger cues to drive intake. Prioritising high-quality protein at every meal can help reduce food noise, improve fullness, and support better results over time.
3. Bottom Line
If your appetite suddenly returns after a dose increase, it doesn’t mean Mounjaro has stopped working. More likely, your body is responding to an energy or protein shortfall. To get back on track:
- Fuel your body with enough calories to meet basic needs
- Include sufficient protein daily
- Maintain a moderate calorie deficit, not an extreme one
Still wondering why your hunger has increased? Find out more about how your body responds to Mounjaro and hunger here.
Supporting your medication with the right nutrition is key to feeling better, reducing food noise, and making sustainable progress.
