Zepbound side effects: what is common and what is serious

Every row of the Zepbound reaction table

Adverse reactions in Zepbound weight-management trials (label Section 6.1, Table 1)

Reaction	Placebo	5 mg	10 mg	15 mg
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%
Indigestion (dyspepsia)	4%	9%	9%	10%
Injection site reactions	2%	6%	8%	8%
Fatigue	3%	5%	6%	7%
Allergic (hypersensitivity) reactions	3%	5%	5%	5%
Burping (eructation)	1%	4%	5%	5%
Hair loss	1%	5%	4%	5%
Reflux (GERD)	2%	4%	4%	5%
Gas (flatulence)	2%	3%	3%	4%
Bloating (abdominal distension)	2%	3%	3%	4%
Dizziness	2%	4%	5%	4%
Low blood pressure	0%	1%	1%	2%

The same label section adds three details. Women reported hair loss at 7.1% and men at 0.5% while on Zepbound. Injection site reactions climbed to 11.3% in people whose bodies made antibodies to tirzepatide. Low blood pressure reached 2.2% among people who also used blood pressure drugs ^[1]. Pooled across the trials, side effects led 4.8% to 6.7% of users to quit, compared with 3.4% of the placebo group ^[1].

Rare but serious: what to watch for

Serious risks in the Zepbound Medication Guide

Risk	Signs to watch for	What to do
Pancreatitis	Belly pain that is severe and does not stop, sometimes felt in the back, with or without nausea or vomiting	Stop Zepbound; call your provider at once
Gallbladder problems	Pain high in the belly, fever, jaundice (yellow skin or eyes), clay-colored stools	Call your provider at once
Kidney problems	Dehydration after diarrhea, nausea or vomiting	Keep drinking fluids; call if the symptoms persist
Serious allergic reaction	Swollen face, lips, tongue or throat; hard to breathe or swallow; severe rash or itch; fainting or dizziness; racing heartbeat	Stop Zepbound and get emergency care
Low blood sugar	Dizziness, sweating, confusion, headache, blurred vision, shakiness, fast heartbeat, anxiety, hunger	Treat it the way your care team showed you; risk is higher with insulin or a sulfonylurea
Vision changes (type 2 diabetes)	Any new change in eyesight	Tell your provider
Aspiration during anesthesia	Stomach contents getting into the lungs during a procedure	Tell every provider about Zepbound before surgery or sedation

The warning printed in a box at the top of the label is about the thyroid. In rats, Zepbound caused C-cell tumors; whether it does so in people is not known. It is not for anyone with a personal or family history of medullary thyroid carcinoma, or with MEN 2. A neck lump, lasting hoarseness, trouble swallowing or shortness of breath should be reported ^[1]. One warning is gone: suicidal behavior and ideation came off the label in February 2026 ^[3].

Sweats, shakes, chills or feeling cold

The Medication Guide lists sweating and shakiness among the signs of low blood sugar, next to a fast heartbeat and a jittery feeling ^[2]. For people without diabetes that problem was uncommon on Zepbound (0.3% vs 0% on placebo). In type 2 diabetes it rose to 4.2% vs 1.3%, and to 10.3% alongside a sulfonylurea ^[1]. Chills, night sweats and feeling cold do not appear in the common-reaction table ^[1]. Fever is one of the gallbladder signs, so chills plus fever or upper belly pain deserve a call to your provider ^[2].

Headaches and chest pain on Zepbound

Headache is missing from the reaction table, but the Medication Guide counts it as a possible low blood sugar signal ^[2]. Chest pain is not in the table either ^[1]. Do not write chest pain off as a drug effect: call 911.

Food and timing

Meals do not matter for the shot. The Medication Guide says Zepbound may be taken with or without food, once a week at any time of day ^[2]. Nausea tends to cluster in the dose-raising months ^[4], one reason the label holds each dose for at least 4 weeks before the next step ^[3]. Steps and timing: Zepbound dosage.

How Zepbound's table compares with Mounjaro's

Zepbound and Mounjaro hold the same molecule, but their tables were built from different patients. In Mounjaro's diabetes trials, nausea was 12% to 18% and diarrhea 12% to 17% on 5 to 15 mg ^[5], below the Zepbound weight-trial rates. We found no head-to-head study of the two brands, so the gap does not mean one is gentler. See Mounjaro vs Zepbound and Mounjaro side effects; semaglutide comparisons are on GLP-1 side effects.

Skin reactions, pens and vials

Redness or other skin reactions where the needle goes in were logged in 6% to 8% of Zepbound users ^[1]. Switch spots each week among the belly, the thigh and, if a helper injects, the back of the upper arm ^[5]. Before each dose the liquid should look clear and colorless to slightly yellow ^[1]. A KwikPen is for one person only, even if you change the needle ^[3]. For the molecule as a whole, including FDA's reports on compounded tirzepatide, read tirzepatide side effects. Medicines and conditions that change how Zepbound is used are on Zepbound interactions.