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

> GLP-1 headache is on the Wegovy (14%) and Saxenda (13.6%) labels and is commonly reported with GH-secretagogue peptides. What to log and how to track it in Peppy.

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

Headache is listed on two GLP-1 labels: Wegovy at 14% versus 10% on placebo, and Saxenda at 13.6% versus 12.6%. It is not among the tabulated reactions for Ozempic, Mounjaro or Zepbound. For research peptides there is no label; headache is commonly reported with growth-hormone secretagogues. Log it 1-5 with hydration and food notes and compare against shot days.

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

A GLP-1 headache is usually a dull, all-over ache that turns up in the first day or two after a shot or in the first week on a new dose. It is the one side effect on this site that spans both of Peppy's audiences: weekly GLP-1 users, and people running research peptides like [CJC-1295 / Ipamorelin](https://peppytracker.com/compounds/cjc-1295-ipamorelin/) or [Ipamorelin](https://peppytracker.com/compounds/ipamorelin/), where it is one of the most commonly reported effects.

The label figures are thin, and honest about it:

| Label | Headache (drug) | Headache (placebo) |
| --- | --- | --- |
| Wegovy 2.4 mg | 14% | 10% |
| Saxenda | 13.6% | 12.6% |
| Ozempic, Mounjaro, Zepbound | not among the tabulated reactions |

Headache is common in any group of people, which is why the placebo numbers are high and the gaps are small. On Saxenda the gap is a single point. For research compounds there is no prescribing information and so no figure at all. Peppy flags headache as common for peptides based on what people report, not on a trial.

## When it tends to show up

No GLP-1 label describes headache timing. The general statement that reactions cluster in dose-escalation weeks is about gut effects.

What people report splits into two stories. The first is a **shot-day headache**: a day or two after a weekly dose, often in the same window as nausea. The second is an **intake headache**: it shows up on days you ate little, drank less than usual, or had diarrhea, and it has more to do with the appetite effect than with the shot itself. The two feel the same. On a chart, the first lines up with shot days and the second lines up with your notes.

For peptide users the rhythm is different. Many people running daily GH secretagogues report headaches in the first few days of a cycle and less often after, and some report them within an hour or two of a shot. Log the time, not just the day, and the pattern shows. The [cycle tracker guide](https://peppytracker.com/guides/peptide-cycle-tracker/) explains how on/off blocks appear on the timeline.

## What is worth logging

- **Severity, 1-5, daily.** If it was a migraine rather than a headache, Peppy tracks [migraine](https://peppytracker.com/side-effects/migraine/) separately; use that one.
- **Hydration and food, in the note.** The single most useful note for this side effect. "Barely drank", "skipped two meals", "normal day".
- **Hours or days since the shot.** For weekly GLP-1s, the day. For daily peptides, the hour matters; log the shot time accurately.
- **The dose, and for peptides the cycle day.** Week one of a new step-up and day three of a new cycle are both natural breakpoints.
- **Dizziness and sleep alongside.** Headache with dizziness suggests dehydration; headache after a bad night suggests sleep. Both are separate scores in Peppy.

## When to contact your prescriber

Headache is not a warning-level reaction on any GLP-1 label. The things it can signal are.

- **Low blood sugar.** Wegovy's label says it "lowers blood glucose and can cause hypoglycemia" and tells prescribers to educate patients on the signs. Headache with shakiness, sweating or confusion is a same-day call, especially if you also take insulin or a sulfonylurea.
- **Dehydration.** The labels link nausea, vomiting or diarrhea leading to dehydration to acute kidney injury. Headache in a diarrhea week with dizziness is that pattern.
- **A sudden, severe, worst-ever headache**, or one with vision changes, stiff neck or weakness. That is an emergency and has nothing to do with tracking.
- **Headaches that get more frequent over weeks.** Not the label's expected direction. Bring the log.

For research peptides, "prescriber" may be a clinic or a doctor who knows what you are taking. The same red flags apply.

## How to do this in Peppy

1. **Turn headache on.** Open Settings ▸ Tracking and toggle Headache. Migraine, Dizziness and Dehydration are in the same list if you want them.
2. **Score it in the daily check-in.** Tap the check-in row on the Today tab. Headache 1-5, sleep and energy 1-5 under feelings, then the hydration note.
3. **Log shots with the real time.** Tap the dose on the Today tab, pick the site on the body map, and adjust the time if you are logging late. For daily peptides that time is what lets you see a same-day pattern. Peppy handles multiple protocols (Pro beyond the first) so a GLP-1 and a peptide stack sit in one log.
4. **Read the weekly heat-map in Progress (Pro).** The headache row lines up with step-up markers for a GLP-1 and with cycle on/off blocks for a peptide. Compare it with the dizziness row below it. Free users see the chart blurred.
5. **Use the Calendar for shot-day detail.** The week strip shows every shot as a dot, colour-coded per protocol. Flip through and compare headache scores on shot days against off days.

Related: the [side-effects tracking guide](https://peppytracker.com/guides/track-glp-1-side-effects-food-noise/), [dizziness](https://peppytracker.com/side-effects/dizziness/), and the [CJC-1295/Ipamorelin tracker](https://peppytracker.com/trackers/cjc-1295-ipamorelin-tracker/).

## Frequently asked

### Does Wegovy cause headaches?

Wegovy's label lists headache in 14% of participants versus 10% on placebo, a four-point gap. Saxenda's lists 13.6% versus 12.6%, a one-point gap. The Ozempic, Mounjaro and Zepbound labels do not list headache among their tabulated reactions.

### Why do GLP-1s cause headaches?

The labels list headache without a cause. Many people report headaches on days they ate or drank very little, or during a diarrhea or vomiting stretch, which points to dehydration and low intake rather than the medicine directly. That is why hydration and food notes matter next to the score.

### Do peptides like ipamorelin or CJC-1295 cause headaches?

There is no prescribing information for research compounds, so no incidence figure exists. Headache is one of the most commonly reported effects with growth-hormone secretagogues in user reports, which is why Peppy flags it as common for peptides. Treat it as anecdote and log your own.

### How long do GLP-1 headaches last?

The labels give no duration for headache. Many people report it in the first day or two after a shot or during the first week on a new dose, then less often. A daily 1-5 score across a month lined up with shot days shows your pattern.

### When is a headache on a GLP-1 serious?

A sudden, severe, worst-ever headache is an emergency regardless of what you take. Wegovy's label warns it can cause hypoglycemia, and the labels link dehydration from GI reactions to acute kidney injury; a headache with dizziness, confusion or very low fluid intake is a same-day call.

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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