Your First Month on a GLP-1 — A Week-by-Week Guide

The pharmacy bag is on the counter. Inside is a pen, a leaflet folded smaller than seems possible, and a box that says 0.25 mg or 2.5 mg. You've read the forums. You know some people sail through the first month and others spend it near the kettle with ginger tea. What you don't know yet is which week will be which for you.

Here's how we'd think about the four weeks, one at a time.

Before the first shot: what's worth sorting out?

A few things are easier to settle before the pen touches skin.

• Pick a shot day you can keep. A calm evening beats a busy Monday morning.
• Read the Instructions for Use for your exact pen. Pens differ between brands.
• Know your brand's missed-dose rule. Mounjaro and Zepbound: within 4 days. Ozempic: within 5 days. Wegovy injection: take it if your next dose is more than 2 days away. Otherwise skip and carry on.
• Check your other medicines with your pharmacist. The labels warn that insulin or sulfonylureas raise the risk of low blood sugar. The tirzepatide labels also say oral birth control may work less well for a while, and advise a non-oral or added barrier method for 4 weeks after starting.

Week 1: what happens after the first dose?

For many people, not much. For others, fullness and queasiness arrive within a day or two. Both are normal starting points; the labels describe the first dose as the beginning of a ramp, and say the 2.5 mg tirzepatide dose isn't a maintenance dose at all.

Stomach side effects — nausea, diarrhea, vomiting, constipation — are the most commonly reported reactions on all four labels. The 2025 joint nutrition advisory suggests smaller meals, not going long stretches without eating, going easy on fatty foods, and keeping up fluids.

Week 2: is there a pattern yet?

Usually this is when it shows. Second shot, second set of days after — and you can start to compare. Did the queasiness arrive at the same point? Was it shorter this time?

That pattern is useful. "Days one and two after the shot, then fine" lets you plan meals, workouts and social plans around it, and it's exactly the kind of detail your prescriber asks about.

Week 3: are you eating enough of the right things?

By now appetite is often lower, and that's when protein, fiber and water quietly slip. The joint advisory names adequate protein (paired with strength training), fiber and hydration as core nutritional priorities during GLP-1 treatment.

Constipation often turns up around here too, especially if fluids and fiber have dropped. It's a common label side effect; tell your prescriber or pharmacist if it's bothering you rather than putting up with it.

Week 4: what happens at the end of the month?

The labels' usual rhythm is to consider the first step up after 4 weeks. Whether it happens then is up to your prescriber. The Wegovy label specifically says that if a dose isn't tolerated, delaying the next step by 4 weeks can be considered. We cover what the next stages look like in moving up a GLP-1 dose.

This is the week to look back rather than forward. Did side effects ease from week one to week four? Were there days you couldn't eat or drink much? Has your weight trend moved the way you and your prescriber expected? Those three answers make the step-up conversation much easier.

What we'd track

1. Each shot, on time. Date, dose and injection site. It's the anchor for everything else, and it makes missed-dose questions easy to answer.
2. Side effects by day after the shot. Nausea, constipation, heartburn, fatigue, rated simply. Four weeks of this shows your pattern.
3. Protein, fiber and water. Not perfect numbers — just whether they're there most days.
4. Weight, a few times a week. Look at the line by week four, not single mornings.
5. Questions for week four. Write them down as they come up.

Holt reminds you on shot day, with a lock-screen Live Activity, and suggests the next injection site in your rotation. Side effects sit against dose days, and meal photos estimate protein and fiber without weighing anything.

Start your first month in Holt

At the end of week four, the doctor-visit report gathers the month on one page, with suggested questions for your appointment. You'll walk in with a month of notes rather than a month of guesses.