Zepbound (Tirzepatide): How It Works, Side Effects and What to Eat

March 10, 2024 · By the Nutrition Solutions for Me team

Zepbound is a prescription medicine, not a workout. It is the brand name for tirzepatide, a once-weekly injection that the FDA approved in November 2023 for long-term weight management. It is used together with a reduced-calorie eating plan and more physical activity.

If you have just started Zepbound, or you’re thinking about it, this guide explains how it works, what side effects to expect, and how to eat so you feel better and keep the results.

Who Zepbound is for

The FDA approved Zepbound for adults who have:

• Obesity (a BMI of 30 or more), or
• Overweight (a BMI of 27 or more) with at least one weight-related condition, such as high blood pressure, type 2 diabetes, high cholesterol or heart disease.

In late 2024 it was also approved to treat moderate to severe obstructive sleep apnea in adults with obesity. The same medicine is sold as Mounjaro for type 2 diabetes. Only your doctor or another licensed prescriber can decide if it’s right for you.

How it works

Tirzepatide copies two natural gut hormones, GLP-1 and GIP, that your body releases after you eat. Together they:

• Help you feel full sooner and stay full longer
• Slow how fast food leaves your stomach
• Help your body release insulin when blood sugar rises

In the main clinical study, people taking the highest dose lost about 21% of their body weight on average over 72 weeks, compared with about 3% for people taking a placebo. Results vary from person to person.

Common side effects

Most side effects affect the stomach and gut, and they are most common when you start or raise the dose:

• Nausea, vomiting or burping
• Diarrhea or constipation
• Stomach pain, bloating or indigestion
• Tiredness
• Redness or itching where you inject

Serious risks to know about

Zepbound has a boxed warning about thyroid C-cell tumors, seen in studies in rodents. It should not be used by anyone with a personal or family history of medullary thyroid cancer or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Other warnings include pancreatitis, gallbladder problems, low blood sugar (mainly when combined with insulin or a sulfonylurea), kidney problems from dehydration, and serious allergic reactions. Zepbound can also make birth-control pills work less well for a while after you start or raise the dose, so ask your prescriber about a backup method. Tell your care team before any surgery or procedure that uses anesthesia.

Call your doctor right away if you have severe stomach pain that doesn’t go away, signs of an allergic reaction, a lump or swelling in your neck, trouble swallowing, or you can’t keep fluids down.

What to eat while taking Zepbound

Because you’ll eat less, every meal matters more. These steps help you feel better and protect your muscle:

1. Put protein first. Include eggs, Greek yogurt, fish, chicken, tofu, paneer, beans or lentils at each meal. Losing weight quickly can mean losing muscle too, and protein (plus strength exercise) helps protect it.
2. Eat smaller meals, slowly. Stop when you feel comfortably full. Overeating is a common trigger for nausea.
3. Go easy on greasy and fried foods. High-fat meals sit in the stomach longer and often make nausea worse.
4. Add fiber gradually. Vegetables, fruit, oats, beans and whole grains help with constipation. Increase them slowly.
5. Drink enough fluids. Sip water through the day, especially if you have vomiting or diarrhea. Dehydration can harm your kidneys.
6. Don’t skip meals entirely. Small, regular meals help you get enough vitamins and minerals.
7. Limit alcohol and sugary drinks. They add calories with little nutrition and can upset your stomach.

Simple meal ideas: Greek yogurt with berries and chia seeds; eggs with sautéed spinach; a lentil soup; grilled fish with roasted vegetables and a small serving of rice; a protein smoothie on low-appetite days.

Planning for the long term

Studies show that many people regain weight after stopping these medicines. Building eating, movement and sleep habits while you take Zepbound gives you the best chance of keeping your results if your dose changes or you stop.

How our dietitians help

Our registered dietitians offer nutrition support for people taking GLP-1 medications, including Zepbound, Wegovy and Ozempic. We help you hit your protein and fluid goals, ease side effects and plan for life after the medication. Visits are in person in Suwanee and Lawrenceville, GA, or by video, and are often covered by insurance (check your plan).

On Zepbound or about to start? Book a visit or call 678-250-3438.

Sources

• U.S. Food and Drug Administration: FDA Approves New Medication for Chronic Weight Management (November 2023)
• U.S. Food and Drug Administration: FDA Approves First Medication for Obstructive Sleep Apnea (December 2024)
• Eli Lilly: Zepbound Prescribing Information and Medication Guide
• Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine, 2022.

This article is general information, not medical advice. Talk with your doctor or a registered dietitian about your own health and medications.

Frequently asked questions

What is Zepbound?

Zepbound is the brand name for tirzepatide, a once-weekly injection made by Eli Lilly. The FDA approved it in 2023 for long-term weight management in adults with obesity, or with overweight plus at least one weight-related health condition. The same medicine is sold as Mounjaro for type 2 diabetes.

How is Zepbound different from Wegovy or Ozempic?

Wegovy and Ozempic contain semaglutide, which acts on one gut hormone receptor (GLP-1). Tirzepatide acts on two (GLP-1 and GIP). Your prescriber decides which medicine, if any, fits your health history.

What are the most common side effects of Zepbound?

The most common are nausea, diarrhea, vomiting, constipation, stomach pain, indigestion and tiredness, especially when starting or raising the dose. Eating smaller meals, slowing down and staying hydrated often helps. Call your doctor if symptoms are severe or don't improve.

What should I eat while taking Zepbound?

Focus on protein at every meal, plenty of vegetables and fiber, enough fluids, and smaller portions. Greasy, fried and very sweet foods often make nausea worse. A registered dietitian can build a plan around your foods and appetite.

Do you prescribe Zepbound?

No. Our registered dietitians provide nutrition care. Your doctor or another licensed prescriber decides on medication. We work alongside them to help you eat well while you take it.