The short answer
- For each symptom, note what it was, how bad it was on a simple 1–5 scale, and when it started relative to your last injection. Add how long it lasted and your dose at the time.
- The Mounjaro and Ozempic leaflets both list digestive effects such as nausea, diarrhoea, vomiting, constipation, indigestion and heartburn. Both say nausea and diarrhoea usually ease over time.
- A diary is valuable because it shows patterns memory misses: whether symptoms cluster a day or two after each dose, or flare after a dose change.
- Some symptoms shouldn't wait for your next appointment. Severe stomach pain that won't go away, or signs of a serious allergic reaction, need urgent medical help.
"How have you been getting on?" is a hard question to answer accurately at a ten-minute appointment. Was the nausea in week three or week five? Did it get better after the first month, or do you just remember the good days? A GLP-1 side-effect diary replaces guesswork with a record your prescriber can actually use.
This guide explains what's worth recording, offers a simple severity scale, and shows how to spot patterns. It also covers when you shouldn't wait for your diary at all. We make JabKeeper, which includes a side-effect diary, but everything here works just as well on paper.
Why a side-effect diary helps
Medicines such as Mounjaro (tirzepatide) and Wegovy or Ozempic (semaglutide) are taken weekly. Their side effects often follow the weekly rhythm too. The UK Mounjaro leaflet notes that its most common side effects are most likely when you first start treatment and decrease over time in most people. A diary is how you find out whether that's true for you.
It helps in three practical ways:
- It beats memory. People tend to remember the worst day and the most recent day. A log records the ordinary days in between.
- It shows patterns. Symptoms that appear a day or two after every injection, or only after a dose step, are easy to see in a log and almost impossible to see without one.
- It makes appointments faster. Your prescriber can make decisions with you based on facts instead of impressions. Those decisions are theirs to make, not the diary's.
What to record for each symptom
| Detail | Example | Why it matters |
|---|---|---|
| Symptom | Nausea | Use the same word each time so entries can be compared. |
| Severity | 3 out of 5 | Shows whether things are improving or getting worse. |
| When it started | Tuesday, 2 days after the dose | Links symptoms to your injection day. |
| How long it lasted | Most of the afternoon | Separates a brief wave from a whole lost day. |
| Dose at the time | Wegovy 1 mg, week 2 on this dose | Shows whether symptoms follow dose changes. |
| Context | Large late meal; not much water | Helps you and your prescriber see possible triggers. |
| What you did | Smaller meals, extra fluids | Records what helped for next time. |
You don't need every field every time. A symptom, a severity and a date are enough for most entries. Add the rest when something is new, severe or unusual.
Symptoms people commonly log
The UK patient leaflets for Mounjaro and Ozempic both list digestive side effects, including feeling sick (nausea), diarrhoea, being sick (vomiting), constipation, indigestion, and reflux or heartburn. Both describe nausea and diarrhoea as very common and say they usually ease over time. Tiredness, reduced appetite and injection-site reactions such as redness or itching also appear in the leaflets.
Your own leaflet has the complete list for your medicine, with how often each side effect occurs. Keep it somewhere you can find it. If a symptom isn't listed or doesn't fit the usual pattern, that's worth raising sooner rather than later.
A simple 1–5 severity scale
A consistent scale matters more than a precise one. Here is the five-point scale JabKeeper uses, with plain descriptions you can apply on paper too:
| Score | Label | What it feels like |
|---|---|---|
| 1 | Mild | You notice it, but it doesn't change your day. |
| 2 | Noticeable | It's on your mind, but you carry on as normal. |
| 3 | Moderate | You adjust what you eat or do because of it. |
| 4 | Bad | It stops you doing some normal things. Contact your prescriber. |
| 5 | Severe | It dominates your day. Get medical advice promptly. |
Scores are for your records. They are not a triage tool. If a symptom feels serious, act on it rather than rating it.
How to spot patterns
After four to six weeks of entries, look back and ask three questions. Do symptoms cluster on particular days after your injection? Did they change when your dose changed? Are they getting milder week by week? A short example makes this easier to picture:
| Week | Dose | Nausea started | Worst severity |
|---|---|---|---|
| 1 | Step 1 | Day 1 after injection | 3 |
| 2 | Step 1 | Day 1 after injection | 2 |
| 3 | Step 2 (new) | Day 1 after injection | 3 |
| 4 | Step 2 | Day 2 after injection | 1 |
In this made-up example, nausea arrives the day after each injection, briefly rises after the dose step, then fades. That is exactly the kind of summary a prescriber can work with in a minute.
Paper, notes or an app?
| Paper or Notes | Spreadsheet | JabKeeper | |
|---|---|---|---|
| Links symptoms to dose day | Manual | With a formula | Shows days since last dose |
| Severity scale | Your own | Your own | 1–5, labelled |
| Four-week summary | No | If you build one | Count, average and worst |
| Custom symptoms | Anything | Anything | Seven common symptoms plus notes |
| Sharing | Show or photograph it | Export or print | Show the screen; no export yet |
Paper and spreadsheets give total freedom over what you record. A dedicated diary is quicker and does the pattern-spotting for you. For a broader comparison of logging methods, see app vs spreadsheet vs paper diary.
How JabKeeper's side-effect diary works
JabKeeper's side-effect diary is part of the one-time $9.99 lifetime unlock. It is built around the entry described above:
- Seven common symptoms: nausea, fatigue, constipation, headache, injection-site reaction, reduced appetite and heartburn, each with a note for anything else.
- A labelled 1–5 severity scale from mild to severe, with the date and time of each entry.
- Timing built in. Each entry shows how many days after your last dose it happened, and you can tag symptoms on a dose entry.
- A four-week summary with the number of entries, the average severity and the worst day.
- A nudge for severe entries. When you log a 4 or 5, JabKeeper suggests contacting your prescriber.
Everything stays on your iPhone, with no account and no analytics. Symptom entries are never written to Apple Health. JabKeeper doesn't diagnose, interpret or advise; it only records what you enter.
Bring a clear history to your next appointment
Log symptoms and severity next to every dose, and see patterns at a glance. Free to start, $9.99 once for the full diary.
Keeping an eye on injection-site reactions? Pair your diary with a simple injection site rotation. If you're on Mounjaro, our Mounjaro tracker guide covers the full weekly routine.
Sources
- Mounjaro KwikPen Patient Information Leaflet, section 4, electronic medicines compendium (UK), checked 14 September 2026.
- Ozempic Patient Information Leaflet, sections 2 and 4, electronic medicines compendium (UK), checked 14 September 2026.
- When to use NHS 111, NHS.
Frequently asked questions
What should I write in a GLP-1 side-effect diary?
For each symptom, note what it was, how severe it was on a consistent scale, when it started relative to your last injection, how long it lasted and your dose at the time. Add context such as meals or fluids when something is new or severe.
Do GLP-1 side effects go away?
The UK leaflets for Mounjaro and Ozempic say nausea and diarrhoea usually ease over time. Everyone is different, so a diary helps you and your prescriber see what is happening for you.
When should I get medical help for a side effect?
The Mounjaro and Ozempic leaflets say to stop the medicine and seek urgent help for severe stomach pain that will not go away, and to get immediate help for signs of a serious allergic reaction. In the UK, call NHS 111 for urgent advice or 999 in an emergency.
Can I share my JabKeeper side-effect history with my doctor?
You can show your side-effect history and four-week summary on your iPhone during an appointment. JabKeeper does not currently export records.