How to Track GLP-1 Side Effects

Why a log beats memory

Ask anyone six weeks into GLP-1 treatment how the nausea has been and you will get an impression, not an answer. Impressions are shaped by the worst day and the most recent day, which are rarely the same day and rarely representative.

A log turns that into something you can actually read. It is also the difference between telling a provider "the nausea has been bad" and telling them "nausea reaching 4 out of 5 on the two days after each shot, starting when we went to 1 mg, easing by day four."

The second one is a conversation about your treatment. The first is a conversation about how you feel today.

The five fields worth recording

What. Name the symptom plainly — nausea, fatigue, headache, constipation, reflux, dizziness.

When. The date and, roughly, the time of day.

How bad. A 1–5 scale. The number matters less in itself than the fact that you use it consistently, which is what makes two entries comparable. Decide once what a 3 means to you and hold to it.

How long. A few hours, all day, several days.

What else was going on. A dose increase, an unusually large or fatty meal, a skipped meal, poor sleep, less water than usual.

Five fields, thirty seconds. Anything heavier than this is the version that gets abandoned around week three — which is, reliably, just before the first dose increase makes the record genuinely valuable.

The field most people miss

Record which day of the shot cycle you are on.

Nearly every GLP-1 side effect pattern is tied to the cycle. These medications peak in the days after an injection and decline across the rest of the week, so symptoms cluster in the first day or two and ease as the week goes on. That shape is covered in more detail in the day-by-day timeline and the half-life explainer.

Without the day number, a list of symptoms is just a list. With it, the shape appears almost immediately — usually within two or three cycles.

If your schedule is not a clean weekly one, use hours or days since your last dose instead. Tracking a non-standard schedule covers why day-of-cycle stops working there.

Log only the days something happens

This is worth stating plainly, because the instinct runs the other way.

You do not need a daily entry. A log that requires a row every day, most of them saying "fine", is a log with a completion obligation attached to it, and completion obligations are what kill tracking habits. Record the days with something to record. The absence of an entry is itself information: it means that day was unremarkable.

The one exception is the first fortnight, where a daily line is genuinely useful because you are establishing a baseline and do not yet know what your normal looks like. After that, switch to exceptions only.

What to look for when you read it back

• Does it track the cycle? Symptoms concentrated on days one and two behave differently from symptoms scattered evenly across the week. Concentrated is the expected shape.
• Does it track the dose? Compare the weeks after a dose increase with the weeks before. Expect a return of symptoms after each step, and expect it to build over two or three weeks rather than arriving immediately.
• Is it easing? Many side effects settle over several weeks at a stable dose. A log shows that; memory usually does not, because you notice you stopped dreading Tuesday some time after it stopped being true.
• Does anything not fit? A symptom with no relationship to the cycle or the dose may have nothing to do with the medication, which is worth knowing too — and worth mentioning, because it may need looking at on its own terms.

Read for what repeats across cycles rather than for the single worst day. The worst day is memorable and is almost never the useful data point.

Turning it into one sentence

The output of all this is a sentence you can say at an appointment in about five seconds.

The structure that works: symptom, severity, when in the cycle, at which dose, and what it did over time.

"Nausea reaching 4 out of 5 on days two and three, since we went to 1 mg, easing by day four. It was 2 out of 5 at the previous dose."

That is a specific, checkable observation, and it is essentially impossible to produce from memory four weeks later. It is the entire argument for the five fields. The guide on preparing for a GLP-1 appointment covers getting the rest onto one page.

Things worth logging alongside

A few extras that repeatedly turn out to explain something:

• Missed or late doses. The most valuable annotation in any tracking history. A late dose two months ago is often the whole explanation for a strange week.
• What you ate before the bad ones. Not a food diary — just the meal that preceded significant nausea. Larger and higher-fat meals come up often enough to be worth checking against your own record.
• Fluid intake, roughly. Reduced appetite tends to reduce drinking too, and dehydration produces symptoms that get attributed to the medication.
• Appetite and food noise. A 1–5 rating on the same scale. It moves faster than weight and tells you more about what the dose is doing.

When not to wait for the pattern

Tracking is for understanding the ordinary ups and downs. It is not a reason to sit on something that worries you.

Contact your provider promptly about severe or persistent abdominal pain, repeated vomiting, signs of dehydration, or any symptom that is getting worse rather than settling — and follow the guidance that came with your specific medication.

A pattern that has not finished forming is not a reason to delay a phone call. The record is there to make the ordinary legible, not to qualify the serious.

This guide is about record-keeping, not medical advice. Your provider is the one who decides what your symptoms mean and what to do about them.