How long does it take for Mounjaro to work?

Key Points

• Mounjaro (tirzepatide) is FDA-approved for type 2 diabetes management and also results in weight loss
• Mounjaro (tirzepatide) starts working in your body immediately after injection, but noticeable effects on blood sugar can take about 4 weeks
• Weight loss results typically begin within a few weeks, with results (15-20% of body weight) possible over 72 weeks
• Combining Mounjaro with a balanced diet and regular exercise maximizes both blood sugar control and weight loss results

Your body responds to Mounjaro (tirzepatide) immediately after injection, though visible results typically take several weeks to appear. This medication works through two hormone pathways to regulate blood sugar and reduce appetite.

Clinical studies show Mounjaro lowers A1C levels and helps with weight loss over time. If you're just getting started, it helps to understand what to expect on Mounjaro.

Gia Eapen, MD, says, "Success with any medication for chronic conditions like type 2 diabetes or chronic weight issues is a journey and not an overnight transformation. Setting realistic expectations about how Mounjaro works can help sustain your health goals over time.”

What is Mounjaro?

Mounjaro (tirzepatide) is an FDA-approved injectable medication to manage type 2 diabetes. It belongs to a class of drugs known as dual GIP and GLP-1 receptor agonists, which help control blood sugar levels by mimicking natural hormones in your body.

While Mounjaro is officially approved to treat type 2 diabetes, many people also experience significant weight loss while taking it. This has made Mounjaro increasingly popular among people looking to lose weight.

However, it's important to note that any off-label use should be discussed with your healthcare provider.

How does Mounjaro work?

Mounjaro works by activating two hormone receptors in your body: the GLP-1 (glucagon-like peptide-1) receptor and the GIP (glucose-dependent insulinotropic polypeptide) receptor.

Mounjaro is designed to:

• Tell the appetite center in the brain that you’re full faster
• Slow your digestion down, helping you feel full for a longer time
• Stimulate the pancreas to release insulin when you eat so that your blood sugar levels do not get too high
• Stops your liver from releasing stored glucose into the blood (preventing high blood sugar levels)

How long does it take for Mounjaro to work?

Mounjaro starts working almost immediately, but you can see real results after a few weeks of regular use.

How long does it take for Mounjaro to lower A1C?

"Mounjaro starts to work immediately after you take the first injection. However, in studies, Mounjaro lowered A1c levels in about four weeks,” Eapen, MD, says. “Studies show that it takes about 8 weeks to reach A1C levels below 7% and 12 weeks to reach A1C levels of 6.5% or lower.”

Think of A1C as your blood sugar's report card over three months. It measures the percentage of your red blood cells with sugar attached. According to the American Diabetes Association (ADA), an A1C less than 7% is a goal for people with diabetes. For people without diabetes, an A1C level less than 5.7% is considered in the normal range.

How long does it take for Mounjaro to work for weight loss?

Although Mounjaro is FDA-approved for type 2 diabetes management only, studies show that people achieved an average of 15-20% weight loss over 72 weeks (about a year and a half).

Impact of Mounjaro dose on diabetes and weight loss

"Mounjaro is available in six different dosages: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg," explains Eapen, MD. "It's administered as a subcutaneous injection, which means it’s injected under the skin.

Typically, doctors start people on Mounjaro with the lowest dose of 2.5 mg to allow their body to adjust to the medication. Then, the dose may be increased gradually to find the optimal level based on how each person’s body responds.

The dosage affects your A1C levels. The tirzepatide Surpass-5 clinical trial showed a 2% reduction in A1C on the 5mg dose, 2.4% on 10mg, and 2.34% on the 15mg dose.

Similarly, the dose affects weight loss as well. Research shows that people taking 5mg of Mounjaro weekly lost an average of 15% of their body weight, while those taking the 10mg dose experienced an average weight loss of about 20%.

Your healthcare provider will recommend the appropriate dosage for you based on your unique medical needs and how your body responds to the medication.

How to optimize results on Mounjaro

Mounjaro is designed to work together with changes in diet and lifestyle. Here’s how to maximize weight loss on Mounjaro:

• The best Mounjaro diet is rich in whole, unprocessed vegetables and fruit, lean proteins, and small amounts of healthy fats and whole grains. The Mediterranean diet is one example
• Regular physical activity can help your muscles absorb glucose from the blood, helping with insulin sensitivity and lowering blood sugar levels. In particular, walking at least 20-30 minutes after a meal (a stroll, not a brisk walk) can help lower blood sugar levels. If you don’t have much time, even a light stroll for 2-5 minutes helps

Not losing weight on Mounjaro? Here are some reasons why

If you've been taking Mounjaro but are not losing weight, there may be many reasons why, including:

• Poor diet: Consuming excess calories or highly processed foods can counteract Mounjaro's appetite-suppressing effects
• Too much sodium: Mounjaro is supposed to reduce your appetite, but consuming too much salt in your diet may result in water retention and weight gain. In particular, watch out for packaged foods and meals from restaurants
• A lack of exercise: Physical activity enhances insulin sensitivity and can help boost your metabolism, which can help you with lowering blood glucose levels and weight loss
• Emotional eating triggers: It’s common to reach for comfort foods during times of stress, boredom, anxiety, and as a treat after a long day. However, if you have food cravings to eat large amounts of foods rich in sugar, refined flours, fats, and salt, they can impact your weight loss, even on a drug like Mounjaro
• The medication needs time to work: It takes several weeks to months to see significant weight changes. Patience is key to managing a long-term chronic condition with medications like Mounjaro
• Dosage adjustment: If you’re not seeing the weight loss results you expect, even after waiting a month or two, you could talk to your doctor about whether your Mounjaro dose is right for you. In studies, greater weight loss was related to higher doses. However, please do not change your dose except under medical supervision

Remember that everyone's body responds differently to medication. Some people experience rapid results, while others may take longer to experience weight loss or lower blood sugar levels.

How can a registered dietitian maximize your results on Mounjaro?

Studies show that people who lost weight on Mounjaro also changed their diet and lifestyle. However, changing eating patterns can be very challenging on your own. Dealing with the side effects of Mounjaro can make it harder to learn what meals may work well for you.

A registered dietitian can:

• Create a personalized nutrition plan that gives you the nutrition you need, even on a reduced appetite
• Help you understand proper portion sizes and adjust meal timings based on your new normal
• Address nutritional deficiencies that may be affecting your metabolism
• Provide strategies to manage common side effects like nausea and gastric discomfort
• Adjust your eating plan as your dosage changes or your body adapts
• Be a trusted sounding board for you as you navigate your new life on Mounjaro

The good news is that many major insurance plans cover nutrition counseling by a registered dietitian, especially for people with chronic conditions like type 2 diabetes.

Final thoughts: How fast does Mounjaro work?

So, how long does Mounjaro take to work? The short answer is that you'll likely notice changes within weeks, but the full benefits unfold over several months.

Within days, you may notice you’re not hungry like before. However, most people begin to see results within 4-8 weeks of starting Mounjaro. The most significant improvements to health parameters typically develop over 3-6 months of consistent use.

Mounjaro works better when paired with nutritious meals and regular movement. A registered dietitian can be your personal guide as you navigate your health journey with Mounjaro.

Lose weight on Mounjaro. Find a weight loss dietitian who accepts your insurance.

Frequently Asked Questions (FAQs)

Does Mounjaro take effect immediately?

Mounjaro starts to work immediately after injection. However, noticeable results typically take weeks to develop. People with diabetes may see lower blood sugar levels in 1-3 months, and participants in clinical studies lost 15-20% of their body weight over 72 weeks.

It’s important to pair Mounjaro with better lifestyle habits such as a balanced diet and regular exercise. Results can vary significantly from person to person.

What to expect in the first week on Mounjaro?

"Your healthcare provider will usually start you on the lowest dose of 2.5mg so that your body can adjust to the medication," says Eapen, MD. “During this initial period, you may experience some side effects, particularly gastrointestinal issues like nausea, vomiting, or diarrhea. Mounjaro begins working right away, but it takes a few weeks to see results.”

How long does it take to start losing weight on Mounjaro?

Clinical studies have shown that people taking Mounjaro lost about 15 to 20% of their body weight over approximately 72 weeks (about a year and a half). Small changes may be noticeable within the first few weeks, but weight loss develops gradually over months.

Keep in mind that lifestyle factors like diet quality, portion sizes, and physical activity level can significantly impact your weight loss results while taking Mounjaro.

How long does Mounjaro stay in your system?

Your body takes 30 days to clear Mounjaro from your system completely.

How do I choose the right Mounjaro dose?

Your healthcare provider will recommend the perfect dosage for your needs. Typically, you will start on the lowest dose (2.5 mg) for a few weeks. Then, depending on how you respond to the drug and the side effects you experience, your dose may be increased gradually. Please do not adjust your dose or stop taking Mounjaro without medical supervision.

Will Mounjaro lower my A1C?

Clinical trials show that Mounjaro lowers A1C levels. On average, A1C levels dropped by 2% on the 5mg dose, 2.4% on the 10mg dose, and 2.34% on the 15mg dose.

What is the difference between Zepbound and Mounjaro?

Both Zepbound and Mounjaro contain tirzepatide as their main ingredient, but they are approved to treat different health conditions. Mounjaro is approved to treat type 2 diabetes, while Zepbound is approved for chronic weight management.

Get the best Mounjaro diet for you. Find a registered dietitian who accepts your insurance.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.