Zepbound Side Effects: How Common Each One Is, by Dose, and What to Eat and Drink

Short answer: The most common Zepbound (tirzepatide) side effects are digestive. In the two main trials on its FDA label, nausea was reported by 25% to 29% of adults across the 5, 10 and 15 mg doses against 8% on placebo, diarrhea by 19% to 23% against 8%, constipation by 11% to 17% against 5% and vomiting by 8% to 13% against 2%.^[1] Most nausea, vomiting and diarrhea came while the dose was being raised and decreased over time, and 4.8% to 6.7% stopped treatment because of an adverse reaction, against 3.4% on placebo.^[1] The label carries a boxed warning about thyroid C-cell tumors, seen in rats.^[1]

New to eating less? Start with what to eat when you're eating less, the guide the rest of Lighter Days builds on.

This page is built from the Zepbound prescribing information and Medication Guide as they stand on November 13, 2026 (label revised August 2026): every adverse reaction in the label's main table, by dose against placebo; when they tend to start; the serious warnings; what to eat and drink for the common digestive ones; and when to call the prescriber. The drug itself, its approvals and its price are on our tirzepatide page.

General information, not medical advice. These are group averages from clinical trials and cannot tell you what you will experience. Anything about your own dose or symptoms is a conversation with your prescriber.

Zepbound side effects by dose: the label table

Table 1 of the label lists every adverse reaction reported by at least 2% of people on Zepbound and more often than on placebo, pooled from SURMOUNT-1 and SURMOUNT-2: 2,519 adults treated for up to 72 weeks.^[1]

Adverse reaction	Placebo (958)	5 mg (630)	10 mg (948)	15 mg (941)
Nausea	8%	25%	29%	28%
Diarrhea	8%	19%	21%	23%
Vomiting	2%	8%	11%	13%
Constipation	5%	17%	14%	11%
Abdominal pain	5%	9%	9%	10%
Dyspepsia (indigestion)	4%	9%	9%	10%
Injection site reactions	2%	6%	8%	8%
Fatigue	3%	5%	6%	7%
Hypersensitivity (allergic) reactions	3%	5%	5%	5%
Eructation (burping)	1%	4%	5%	5%
Hair loss	1%	5%	4%	5%
Gastroesophageal reflux (heartburn)	2%	4%	4%	5%
Flatulence	2%	3%	3%	4%
Abdominal distension (bloating)	2%	3%	3%	4%
Dizziness	2%	4%	5%	4%
Hypotension (low blood pressure)	0%	1%	1%	2%

Source: Zepbound prescribing information, section 6.1, Table 1; group sizes in brackets.^[1] Two patterns stand out. Nausea is about as common on 5 mg as on 15 mg, while vomiting and diarrhea rise with the dose. Constipation runs the other way, highest on 5 mg. The label also warns that rates from one drug's trials cannot be compared directly with another's.^[1]

What are the most common side effects of Zepbound?

The label names twelve reactions reported by at least 5% of people on Zepbound: nausea, diarrhea, vomiting, constipation, abdominal pain, dyspepsia, injection site reactions, fatigue, hypersensitivity reactions, eructation, hair loss and gastroesophageal reflux disease.^[1] Taken together, digestive reactions were reported by 56% on each dose against 30% on placebo.^[1]

Some of the other figures in section 6.1 are worth knowing:^[1]

• Allergic reactions within a day of a dose were reported by 2.1% against 0.4% on placebo; most were skin reactions such as rash or itching.
• Injection site reactions were much more frequent in people who developed antibodies to tirzepatide (11.3%) than in those who did not (1%).
• Hair loss was tied to weight reduction and reported far more often by women than men: 7.1% against 0.5%. Nobody on Zepbound stopped treatment because of it. More on this in does Zepbound cause hair loss.
• Low blood pressure was reported by 1.6% against 0.1%, and more often in people also taking blood pressure medicine (2.2%) than in those who were not (1.2%).
• Heart rate rose by an average of 1 to 3 beats per minute, against no increase on placebo.
• Less common: dry mouth or throat (1% against 0.1%), a changed sense of taste (0.4% against none) and dysesthesia, an unusual skin sensation (0.2% to 0.4% against 0.1%).

Are tirzepatide side effects the same on Mounjaro?

Mounjaro is the same molecule, approved for type 2 diabetes, and its label reports lower rates from different trials in a different population. In its placebo-controlled diabetes trials, nausea was reported by 12%, 15% and 18% on 5, 10 and 15 mg against 4% on placebo; diarrhea by 12%, 13% and 17% against 9%; decreased appetite by 5%, 10% and 11% against 1%; vomiting by 5%, 5% and 9% against 2%; and constipation by 6%, 6% and 7% against 1%.^[2] The two sets of numbers come from different trials, so they are not a ranking.

When do Zepbound side effects start, and how long do they last?

The label is specific on the digestive ones: the majority of nausea, vomiting and diarrhea events occurred during dose escalation and decreased over time.^[1] Most people who stopped Zepbound because of an adverse reaction did so during the first few months, mostly for digestive reasons.^[1] Tirzepatide slows stomach emptying, and the label says that delay is largest after the first dose and lessens over time.^[1]

That is why the label raises the dose slowly. The schedule below is what the label says, reproduced so you can see why the first weeks and each step up are the bumpy ones; your prescriber sets your dose.^[1]

What the FDA label says — not dosing advice. Zepbound, once weekly.^[1]

Step	What the label says
Weeks 1 to 4	2.5 mg, a starting dose only, not a maintenance dose
After 4 weeks	5 mg
Each later step	Up by 2.5 mg, after at least 4 weeks on the current dose, "to reduce the risk of gastrointestinal adverse reactions"
Maintenance	5, 10 or 15 mg; the label says to consider a lower maintenance dose if one is not tolerated

Other reactions run on their own clocks. Allergic reactions counted as "immediate" came within a day of a dose.^[1] Hair shedding of the kind usually linked to rapid weight change, telogen effluvium, typically starts a few months after the trigger and usually grows back.^[3][4]

What are the serious side effects of Zepbound?

These are the label's boxed warning and warnings and precautions, in the order the label gives them.^[1]

Warning	What the label reports
Thyroid C-cell tumors (boxed warning)	Tirzepatide caused them in rats; whether it does in humans is unknown. Not for anyone with a personal or family history of medullary thyroid carcinoma or with MEN 2.
Severe digestive reactions	1.7%, 2.5% and 3.1% on 5, 10 and 15 mg against 1% on placebo. Not recommended with severe gastroparesis.
Acute kidney injury from fluid loss	0.5% against 0.2% in trials. Post-marketing reports, some needing dialysis, came mostly after nausea, vomiting or diarrhea led to dehydration.
Acute gallbladder disease	Gallstones 1.1% against 1%; gallbladder inflammation 0.7% against 0.2%; gallbladder removal 0.2% against none. Linked to weight reduction.
Acute pancreatitis	Confirmed in 0.2% in both groups in the weight trials; fatal and non-fatal cases have been seen with GLP-1 medications and Zepbound.
Serious allergic reactions	Anaphylaxis and angioedema reported after approval; severe reactions in 0.1% in trials against none on placebo.
Low blood sugar	4.2% against 1.3% in people with type 2 diabetes, and 10.3% in those also taking a sulfonylurea. Also reported in adults without diabetes.
Diabetic eye disease (type 2 diabetes)	Temporary worsening of diabetic retinopathy has been reported with rapid improvement in blood sugar.
Breathing in stomach contents under anesthesia	Rare post-marketing reports with GLP-1 medications; tell every healthcare provider before a planned procedure.
Never share a KwikPen	Sharing a pen, even with a new needle, risks passing on blood-borne infections.

Source: Zepbound prescribing information, boxed warning and sections 5 and 6.1.^[1] After approval, ileus, intestinal obstruction and severe constipation including fecal impaction have also been reported with tirzepatide.^[1] The label's list of recent changes shows a warning on suicidal behavior and ideation removed in February 2026.^[1]

Two interactions belong here too. Because stomach emptying slows, the label advises people taking birth control pills to switch to a non-oral method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase.^[1] And Zepbound should not be used with other tirzepatide products or with any GLP-1 receptor agonist.^[1]

What to eat and drink for the common digestive side effects

Food will not change what a medication does, but the 2025 joint advisory on nutrition with GLP-1 therapy, from four US medical and nutrition societies, gives practical steps for each symptom.^[5]

What you notice	What the sources suggest	Our page on it
Queasy, especially in the morning or after a long gap	A small breakfast, then something small every 3 to 4 hours; low-fat, not-too-rich foods; ginger or peppermint tea among the foods to encourage[5]	What to eat on queasy days
The first days after a dose increase	Go easy on fatty and high-fiber foods for a few days, when symptoms are more likely[5]	What to eat on queasy days
Vomiting or diarrhea	Fluids on a schedule; the Medication Guide calls drinking fluids important to lower the chance of dehydration[5][1]	GLP-1 dehydration
Constipation	Manage it early, with fluids and fiber from food added gradually[5]	Zepbound and constipation and GLP-1 constipation
Heartburn, burping, a sour taste	Smaller, lower-fat meals; the advisory notes alcohol can make reflux worse[5]; avoid meals within 2 to 3 hours of bedtime[6]	What to eat on queasy days
Full after a few bites	Small, frequent meals, protein first; smoothies, protein drinks, cottage cheese and soups are often easier than heavier foods[5]	What to eat on Zepbound
Hair shedding	Usually temporary and grows back;[3][4] the advisory puts protein first among nutrition priorities on any GLP-1[5]	Does Zepbound cause hair loss

Two tools turn these into numbers: the hydration calculator gives a starting fluid target, and the protein calculator splits a daily protein target into small meals.

When should you call your prescriber about a Zepbound side effect?

The Zepbound Medication Guide is plain about these.^[1]

• Get medical help right away for signs of a serious allergic reaction: swelling of the face, lips, tongue or throat; problems breathing or swallowing; severe rash or itching; fainting or feeling dizzy; a very rapid heartbeat. The Guide says to stop using Zepbound.
• Stop using Zepbound and call right away for severe pain in the stomach area that will not go away, with or without vomiting, sometimes felt through to the back. That can be pancreatitis.
• Call right away for nausea, vomiting or diarrhea that does not go away, which can lead to dehydration and kidney problems, and for possible gallbladder symptoms: pain in the upper stomach, fever, yellowing of the skin or eyes, or clay-colored stools.
• Tell your prescriber about stomach problems that are severe or will not go away; a lump or swelling in the neck, hoarseness, trouble swallowing or shortness of breath; and, with type 2 diabetes, any change in vision.
• Know the signs of low blood sugar if you also take insulin or a sulfonylurea: dizziness, sweating, confusion, headache, blurred vision, shakiness, a fast heartbeat, hunger or weakness.
• Before any surgery or procedure, tell every healthcare provider that you take Zepbound.

The Guide also says to talk to your healthcare provider about any reaction that bothers you or does not go away. Suspected adverse reactions can be reported to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.^[1]

A smaller appetite puts more weight on what does get eaten. The nutrition gap calculator shows which vitamins and minerals a smaller plate tends to miss, and every approved and investigational medicine in this class is listed in our GLP-1 medications hub.

For transparency about why this page exists on our site: we make one product, Zornava Replenish, a lemon-lime daily hydration and nutrient powder for lighter appetite days, including for people on GLP-1 medications. It is a dietary supplement, not a medication, and it does not replace or imitate any medicine on this page. It is not on sale yet; early access opens February 9, 2027, and the early-access list is open now.