# Heartburn on GLP-1s: what to track, when it tends to show up, and how to log it

> GLP-1 heartburn shows on the labels as GERD (Wegovy 5%, Zepbound 4-5%) and dyspepsia (up to 10%). When it hits, what to log, and how to track it in Peppy.

Source: https://peppytracker.com/side-effects/heartburn/
Last updated: 2026-08-30

Heartburn appears on GLP-1 labels under two names. Gastroesophageal reflux disease is listed for Wegovy (5% vs 3% placebo), Zepbound (4-5%), Saxenda (4.7%) and Ozempic (1.9%). Dyspepsia is higher: Wegovy 9%, Zepbound 9-10%, Mounjaro 5-8%, Saxenda 9.6%. Log severity 1-5 daily with a meal note, and line it up against shot days and dose step-ups.

## GLP-1 heartburn: what it is and who reports it

GLP-1 heartburn is the burning behind the breastbone, the sour taste, the feeling that dinner is still sitting there at bedtime. Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) slow gastric emptying, and many people report reflux as one of the ways that shows up. It is quieter on the labels than nausea, partly because the labels split it across two terms.

| Label | GERD (drug / placebo) | Dyspepsia (drug / placebo) |
| --- | --- | --- |
| Wegovy 2.4 mg | 5% / 3% | 9% / 3% |
| Zepbound 5 / 10 / 15 mg | 4% / 4% / 5% vs 2% | 9% / 9% / 10% vs 4% |
| Mounjaro 5 / 10 / 15 mg | not tabulated | 8% / 8% / 5% vs 3% |
| Saxenda | 4.7% / 1.7% | 9.6% / 2.7% |
| Ozempic 0.5 / 1 mg | 1.9% / 1.5% vs 0% | 3.5% / 2.7% vs 1.9% |

"Dyspepsia" is the label word for indigestion: discomfort or burning in the upper abdomen. "GERD" is reflux specifically. People do not always draw the line the same way the label does, so Peppy tracks heartburn and [indigestion](https://peppytracker.com/side-effects/indigestion/) as separate side effects and lets you pick. Compounded [Compounded Semaglutide](https://peppytracker.com/compounds/semaglutide-compounded/) and [Compounded Tirzepatide](https://peppytracker.com/compounds/tirzepatide-compounded/) have no label; the branded numbers are your reference.

## When it tends to show up

The labels group every gastrointestinal reaction together when they talk about timing. Wegovy's says they "were most frequently reported during dosage escalation". Mounjaro's and Zepbound's say most nausea, vomiting and diarrhea "occurred during dose escalation and decreased over time". Heartburn is not called out separately.

What people report fills in the rest. Many say heartburn is a meal-timing problem more than a shot-day problem: it flares after large or late meals, and it flares more in the days after a shot when the stomach is slowest. Many also say it gets noticeably worse for a week or two after each step-up. If you are on Wegovy the steps are every four weeks; on Zepbound at least four weeks apart. Circle those dates.

The useful test is whether your worst heartburn days are your biggest-meal days, your shot days, or both. A log answers that in a few weeks.

## What is worth logging

- **Severity, 1-5, daily.** Score the worst moment of the day, and score it at the same time each evening so the numbers compare.
- **Meal size and timing in the note.** "Late dinner", "big lunch", "ate lying down" is enough. You are leaving context, not counting anything.
- **Days since your shot.** Log the shot in the same app and the offset is automatic.
- **The dose you were on.** Heartburn at 0.5 mg and heartburn at 1.7 mg are separate baselines.
- **Sulfur burps and nausea alongside.** They often move together. See [sulfur burps](https://peppytracker.com/side-effects/sulfur-burps/) and [nausea](https://peppytracker.com/side-effects/nausea/).

If your prescriber suggests a change, log the day it started so its effect on the score is visible.

## When to contact your prescriber

Heartburn is not a red-flag reaction on any GLP-1 label. Some things near it are.

- **"Persistent or severe abdominal pain (sometimes radiating to the back), and which may or may not be accompanied by nausea or vomiting."** This is the pancreatitis warning on every GLP-1 label, and upper-abdominal burning that becomes a deep, constant pain is not heartburn.
- **Chest pain that is not obviously reflux.** That is not a tracking question. Treat it as an emergency.
- **Vomiting, or trouble swallowing.** The labels link vomiting-driven dehydration to acute kidney injury. Difficulty swallowing is a separate reason to call.
- **Daily heartburn that is not settling after a step-up.** The labels say to consider delaying escalation if a dose is not tolerated. Your prescriber makes that call; the log makes it a short conversation.

## How to do this in Peppy

1. **Confirm heartburn is on.** It is one of the five GLP-1 defaults. If you need it, open Settings ▸ Tracking and toggle Heartburn. Indigestion and Sulfur burps are in the same list.
2. **Score it in the daily check-in.** On the Today tab tap the check-in row. Set heartburn 1-5, write the meal note, add weight if you weighed in. The check-in counts toward your streak.
3. **Log shots with the body map.** Tap the dose on the Today tab, tap the site on the silhouette, confirm the time. The dose you were on is saved with it, so your titration ladder (Pro) turns into step-up markers on your charts.
4. **Read the weekly heat-map in Progress (Pro).** The heartburn row sits under nausea and sulfur burps, all on the same week axis with step-ups marked. Three rows darkening together after a marker is a different story from heartburn on its own. The free tier shows the chart blurred.
5. **Use the Calendar for the meal-versus-shot question.** The week strip shows shot days. Flip through check-ins and compare the score on day one after a shot with day six. If the notes say "big dinner" on every bad day regardless of shot day, you have your answer.
6. **Export before an appointment (Pro).** Settings ▸ Export produces a PDF or CSV of doses and check-ins. The [export guide](https://peppytracker.com/guides/export-dose-log-for-your-doctor/) covers what is in it.

Related: the [side-effects tracking guide](https://peppytracker.com/guides/track-glp-1-side-effects-food-noise/), the [Ozempic tracker](https://peppytracker.com/trackers/ozempic-tracker/) and the [Mounjaro tracker](https://peppytracker.com/trackers/mounjaro-tracker/) pages.

## Frequently asked

### Does Ozempic cause heartburn?

Ozempic's label lists gastroesophageal reflux disease in 1.9% of patients at 0.5 mg and 1.5% at 1 mg versus 0% on placebo, and dyspepsia in 3.5% and 2.7% versus 1.9%. The higher-dose Wegovy label lists GERD at 5% and dyspepsia at 9%.

### Why do GLP-1s cause acid reflux?

The labels do not give a mechanism for reflux specifically. GLP-1 medicines slow gastric emptying, and many people report that food sitting longer in the stomach is what seems to bring on the burn, especially after large or late meals. That is why the meal note matters in a log.

### How long does GLP-1 heartburn last?

The labels do not give a duration for heartburn or dyspepsia. They say gastrointestinal reactions as a group were reported most often during dose escalation and decreased over time. Many people report heartburn tracks with meals more than with the calendar, so a daily score with a food note shows your pattern faster than waiting.

### Is heartburn on Mounjaro worse at higher doses?

Not clearly. Mounjaro's label lists dyspepsia at 8%, 8% and 5% for 5, 10 and 15 mg versus 3% on placebo. Zepbound's label lists GERD at 4%, 4% and 5% and dyspepsia at 9%, 9% and 10%. These are trial averages, not a dose-response you can apply to yourself.

### When is heartburn on a GLP-1 a reason to call the doctor?

The labels flag persistent or severe abdominal pain, sometimes radiating to the back, with or without nausea or vomiting, as possible pancreatitis. Chest pain that is not clearly heartburn is its own emergency. Heartburn that is new, daily and not settling is worth a prescriber conversation with your log in hand.

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Peppy is a tracking tool, not medical advice. Dose calculations are mathematical conversions only. Always follow your prescriber's instructions and verify every draw-up yourself.

Peppy is a free iPhone app (Pro subscription optional). App Store: https://apps.apple.com/us/app/peptide-tracker-peppy/id6775005514