Constipation on Zepbound (tirzepatide): Incidence, Severity, and Realistic Expectations

How common is constipation on Zepbound?

The rates come from a pool of two placebo-controlled trials, SURMOUNT-1 and SURMOUNT-2, which enrolled 2,519 treated adults with obesity or overweight, with or without type 2 diabetes, for up to 72 weeks plus a 4-week follow-up off drug [1]. Mean age was 47 years, mean BMI 37.4, and 25% of participants had type 2 diabetes [1].

The Zepbound label's pooled weight-management trial table [1]:

Constipation appears in the label's table of common adverse reactions, meaning it occurred in at least 2% of treated patients and more often than on placebo, and it is also named among the most common reactions reported in 5% or more [1]. The label's count includes hard stools as well as constipation itself [1]. At the 5 mg dose, only nausea (25%) and diarrhea (19%) were reported more often than constipation (17%) [1].

A meta-analysis of six randomized trials in adults with overweight or obesity and no diabetes put the relative risk of constipation with tirzepatide at 2.85 (95% CI 2.38 to 3.42) versus placebo [4].

Does the rate rise with the dose?

No. The pattern in the table is 17% at the starting maintenance dose of 5 mg, then 14% at 10 mg and 11% at 15 mg [1]. It does not support the assumption that a higher Zepbound dose automatically means more constipation. The groups are not identical, though: SURMOUNT-2 tested only the 10 mg and 15 mg doses, so the 5 mg group comes from SURMOUNT-1 alone [1].

How severe is it, and how often does it stop treatment?

The label reports severe gastrointestinal adverse reactions as a single combined category rather than constipation on its own: 1.7% on 5 mg, 2.5% on 10 mg and 3.1% on 15 mg, against 1% on placebo [1].

Stopping treatment is also uncommon but dose-related. Overall discontinuation for any adverse reaction was 4.8%, 6.3% and 6.7% at 5, 10 and 15 mg versus 3.4% on placebo, and discontinuation for gastrointestinal reasons specifically was 1.9%, 3.3% and 4.3% versus 0.5% [1]. The label notes that most people who stopped Zepbound because of adverse reactions did so in the first few months, and that those reactions were gastrointestinal [1].

The label also says Zepbound is not recommended in patients with severe gastroparesis [1]. A 2026 narrative review of GLP-1 receptor agonist safety, which includes tirzepatide, lists gastroparesis and bowel obstruction among additional gastrointestinal complications reported and says they may warrant caution in susceptible people [5].

How long does it last?

The Zepbound label gives no constipation-specific timeline. It says the majority of nausea, vomiting and diarrhea events happened during dose escalation and decreased over time, and that most people who stopped Zepbound for adverse reactions did so in the first few months because of gastrointestinal reactions [1].

Dose escalation is built into the schedule: 2.5 mg once weekly for 4 weeks, then 5 mg, with increases of 2.5 mg only after at least 4 weeks on the current dose [1]. Zepbound delays gastric emptying, and that delay is largest after the first dose and diminishes over time [1]. A 2026 review of GLP-1 receptor agonist tolerability says gastrointestinal side effects generally emerge during dose escalation and resolve over time [5].

What the label says about dose changes

The label instructs prescribers to consider treatment response and tolerability when selecting a maintenance dose, and to consider a lower maintenance dose if a maintenance dose is not tolerated [1]. Zepbound maintenance doses for weight reduction are 5, 10 or 15 mg weekly, and for obstructive sleep apnea 10 or 15 mg weekly [1]. The 2.5 mg dose is for treatment initiation and is not approved as a maintenance dose [1].

What has evidence behind it for constipation

The joint American Gastroenterological Association and American College of Gastroenterology guideline on chronic idiopathic constipation in adults strongly recommends polyethylene glycol, sodium picosulfate, linaclotide, plecanatide and prucalopride, and conditionally recommends fiber, lactulose, senna, magnesium oxide and lubiprostone [2]. These recommendations concern chronic idiopathic constipation, not constipation specifically during Zepbound treatment [2].

The MiraLAX Drug Facts label directs adults 17 and older to dissolve 17 g of polyethylene glycol in 4 to 8 ounces of beverage once a day, says the product relieves occasional constipation and generally produces a bowel movement in 1 to 3 days, and limits self-use to no more than 7 days [6]. Its warnings section also covers nausea, vomiting or abdominal pain, and a sudden change in bowel habits lasting over 2 weeks [6].

Two small trials in chronic constipation tested foods and activity rather than drugs. In an 8-week single-blind crossover trial, 40 constipated adults took either dried plums 50 g twice daily or psyllium 11 g twice daily for 3 weeks each; complete spontaneous bowel movements per week and stool consistency improved significantly more with prunes, while straining and global symptom relief did not differ [7]. In a trial of 43 inactive adults over 45, a 12-week program of brisk walking plus an 11-minute daily home routine was followed by fewer incomplete bowel movements, fewer that required straining and fewer hard stools, with total colonic transit time falling from 79.2 to 58.4 hours [8]. Neither trial involved people taking tirzepatide.

Warning signs with constipation

NIDDK describes constipation as fewer than three bowel movements a week, stools that are hard, dry or lumpy, stools that are difficult or painful to pass, and a feeling that not all stool has passed [3].

The same source lists these symptoms as ones that call for a doctor right away when they accompany constipation: bleeding from the rectum, blood in the stool, constant abdominal pain, inability to pass gas, vomiting, fever, lower back pain, or losing weight without trying [3]. The Zepbound label separately notes that severe gastrointestinal reactions can occur and that the drug is not recommended in severe gastroparesis [1].