From the FDA label & pivotal trialsReviewed 2026-05-31

Zepbound Side Effects: What to Expect

Adverse reactions reported for tirzepatide in its pivotal trial program, plus the boxed warning and serious warnings from the FDA label.

WeightLossRankings.org is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Most Common Zepbound Side Effects

Adverse reactions reported in the Zepbound FDA label, with the incidence among tirzepatide-treated patients and placebo for comparison. Figures are transcribed from the label's adverse-reactions section (DailyMed SetID 487cd7e7-434c-4925-99fa-aa80b1cc776b).

Adverse reactionIncidence (Zepbound vs placebo)
Nausea25–29% (placebo 8%)
Diarrhea19–23% (placebo 8%)
Vomiting8–13% (placebo 2%)
Constipation11–17% (placebo 5%)
Abdominal pain9–10% (placebo 5%)
Dyspepsia9–10% (placebo 4%)
Injection-site reactions6–8% (placebo 2%)
Fatigue5–7% (placebo 3%)
Hypersensitivity reactions5% (placebo 3%)
Eructation (burping)4–5% (placebo 1%)
Hair loss (alopecia)4–5% (placebo 1%)
Gastroesophageal reflux disease (GERD)4–5% (placebo 2%)

Source: Zepbound FDA prescribing information via DailyMed (SetID 487cd7e7-434c-4925-99fa-aa80b1cc776b), Section 6 Adverse Reactions. Last verified 2026-05-31. This is summary information — read the full label and talk to a prescriber.

Boxed Warning — Thyroid C-Cell Tumors

In rats, tirzepatide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether ZEPBOUND causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, as the human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined. ZEPBOUND is contraindicated in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Verbatim from the Zepbound FDA label (DailyMed SetID 487cd7e7-434c-4925-99fa-aa80b1cc776b). The boxed warning is the FDA's most serious warning. Do not start Zepbound without discussing your personal and family medical history with a licensed prescriber.

Serious Warnings & Precautions

Beyond the common reactions above, the Zepbound label lists these serious risks (Section 5 Warnings & Precautions). They are less common but can be medically urgent — know the symptoms and when to seek care.

  • Risk of thyroid C-cell tumors
  • Severe gastrointestinal adverse reactions
  • Acute kidney injury due to volume depletion
  • Acute gallbladder disease
  • Acute pancreatitis
  • Hypersensitivity reactions
  • Hypoglycemia
  • Diabetic retinopathy complications in patients with type 2 diabetes mellitus
  • Pulmonary aspiration during general anesthesia or deep sedation

Compare every Zepbound provider

A prescriber screens for the warnings above before prescribing. See current pricing, verification status, form, and states served across every vetted provider in one place.

For management steps and the underlying evidence on each symptom, read our dedicated articles:

GLP-1 side-effect timeline tool →

Frequently Asked Questions