GLP-1 side effects: keeping a record your prescriber can use

By Tessaro Pty Ltd, the maker of Pepti · Reviewed November 2026 · For adults 18+

“The sulfur burps were the absolute worst.” “Does this get better?” Side effects are the most-discussed part of weekly GLP-1 treatment. This page covers what the US labels list, what a dated record can and cannot do, and what to write down. It does not say what to change; that decision belongs with whoever directs your care.

What the labels list

The US prescribing information for the two weekly GLP-1 medicines approved for weight management lists a similar family of common reactions. For semaglutide, the most common adverse reactions (reported in five percent or more of patients) include nausea, diarrhoea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia, dizziness, abdominal distension, eructation (belching), flatulence, gastro-oesophageal reflux disease and hair loss. For tirzepatide the list includes nausea, diarrhoea, vomiting, constipation, abdominal pain, dyspepsia, injection site reactions, fatigue, hypersensitivity reactions, eructation, hair loss and gastro-oesophageal reflux disease.

The tirzepatide label adds that the majority of nausea, vomiting and diarrhoea events occurred while the dose was being stepped up and decreased over time. A review of the semaglutide weight-management trials describes the gastrointestinal events as the most common adverse events, mostly transient and mild to moderate, and says they typically resolved without people stopping treatment permanently (Amaro et al., 2022).

Outside trials, side effects are one of the main reasons people stop. In a large US health-records cohort, moderate or severe gastrointestinal adverse events were associated with a higher rate of stopping (Rodriguez et al., 2025). In a 2025 national survey of US adults who had stopped a GLP-1 medicine, side effects were the second most-cited reason, after cost (DiStefano et al., 2026).

What a record can and cannot do

A record cannot tell you whether a symptom will settle, what is causing it, or what to do about it. Whether to keep going, slow the schedule, hold a shot or stop is a clinical decision. The patient information for both medicines tells people to talk to their healthcare provider about any side effect that bothers them or does not go away, and to stop and call their provider right away for severe pain in the stomach area that will not go away, with or without nausea or vomiting. Warning signs like that are not something to log and wait on.

What a record can do is turn “I’ve felt awful lately” into something specific: which days, how bad, how long, and how that lines up with the shot. That is the detail a prescriber, nurse or pharmacist asks for, and it is the detail that memory blurs within a week. Written down, it also shows you whether the rough days are clustering, thinning out or getting worse, which is useful to bring up rather than to act on alone.

What to write down

• The shot — the day and time you took it, and the site.
• How you feel — on shot day and the days after. “Fine”, “a bit off” or “rough” is enough to see a pattern.
• The symptom itself — nausea, burps, constipation, diarrhoea, heartburn, headache, tiredness, dizziness, hair shedding, or a reaction at the injection site.
• How long and how much — when it started, when it eased, and whether it stopped you eating, working or sleeping.
• Context you suspect matters — a large or rich meal, alcohol, a missed meal, poor sleep. Note it as a suspicion, not a conclusion.
• Questions for the next appointment — written when you think of them, so they are not lost by the time you are in the room.

Keep it short. A record you keep every week is worth more than a detailed one you abandon after ten days.

How Pepti keeps it

After you log a shot, Pepti’s Today screen shows a check-in card that asks “How are you feeling?” with three answers — Fine, A bit off, Rough — plus side-effect chips and a note. The check-in is dismissible and never arrives as a notification. Entries go into a side-effect log that is charted beside your shot days, and into the clinic report you can share from Progress before an appointment. The card closes with one line: “If a side effect is severe or doesn’t settle, contact your prescriber.” Pepti never suggests changing, holding or skipping a shot, and it does not interpret symptoms.

If you add your next appointment in Settings, Pepti can remind you the day before and keeps the clinic report ready to share.

Sources (5)

1. Semaglutide injection (weight management) — US prescribing information, section 6, most common adverse reactions; patient information on side effects and severe stomach pain. FDA label (DailyMed)
2. Tirzepatide injection (weight management) — US prescribing information, section 6, most common adverse reactions and their timing; patient information on side effects and severe stomach pain. FDA label (DailyMed)
3. Amaro A, Sugimoto D, Wharton S, Postgraduate Medicine, 2022 — review of the STEP trials of semaglutide in weight management; the abstract describes the gastrointestinal events as transient, mild to moderate and typically resolving without permanent discontinuation. PubMed 36691309
4. Rodriguez PJ et al., JAMA Network Open, 2025 — discontinuation and reinitiation among US adults with overweight or obesity; the abstract associates moderate or severe gastrointestinal adverse events with a higher hazard of discontinuation. PubMed 39888616
5. DiStefano MJ et al., Journal of Managed Care & Specialty Pharmacy, 2026 — national survey of US adults who stopped a GLP-1 medicine; the abstract lists cost, side effects and lack of insurance coverage as the most-cited reasons. PubMed 42504813

Common questions

Do GLP-1 side effects get better over time?

The tirzepatide label says the majority of nausea, vomiting and diarrhoea events occurred while the dose was being stepped up and decreased over time, and a review of the semaglutide trials describes the gastrointestinal events as mostly transient and mild to moderate. Your own course can differ. If a side effect is severe or does not settle, contact your prescriber.

Should I lower or skip a shot because of side effects?

That is a decision for your prescriber, not for a website or an app. Bring a dated record of what happened and when; it makes the conversation specific.

What should I write down about side effects?

The day and time of each shot, how you felt that day and the days after, the specific symptom, how long it lasted, and whether it stopped you eating, working or sleeping.

Does Pepti tell me what to do about side effects?

No. Pepti records what you log, charts it beside your shot days and puts it in a clinic report you can share. It never suggests changing, holding or skipping a shot.

This page describes record-keeping only. It does not recommend any medicine, dose or schedule, and it does not interpret symptoms.

For adults 18+. Not medical advice. Pepti is a record-keeping tool, not a medical device.

Written with AI assistance and checked against the cited sources. Not medical advice.

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