--- title: "Your First Month on a GLP-1, Week by Week | GLPMate" url: https://glpmate.me/learn/first-month-on-glp-1 language: en description: "What happens in weeks 1–4 on a GLP-1: starter doses, rising levels, appetite changes, side-effect timing, and what to track from day one." updated: 2026-07-22 --- [GLP-1 guides](/learn) # Your first month on a GLP-1, week by week Based on FDA prescribing information & peer-reviewed sources · Updated 2026-07-22 · 8 min read Quick answer Month one is the accumulation month: you start on a low intentionally sub-therapeutic dose (0.25 mg semaglutide / 2.5 mg tirzepatide), your level climbs each week toward steady state, appetite effects appear gradually, and mild GI side effects — if any — usually cluster after dose days and ease as your body adapts. Track from day one; your week-12 self will thank you. ## Before week 1: what the starter dose is (and isn’t) Semaglutide starts at **0.25 mg weekly**, tirzepatide at **2.5 mg weekly** — and both labels are explicit that these starter doses exist for _tolerability_, not effect. If week one feels underwhelming, nothing is wrong. Your treatment hasn’t really started yet; your gut is being introduced to it politely. ## Week 1: the introduction - **Level:** a single dose’s worth — the lowest it will ever be. Peaks 1–3 days after injection. - **Appetite:** some people notice quieter “food noise” within days; many notice nothing yet. Both are normal. - **Side effects:** if any, usually mild queasiness or fatigue in the 48 hours after the shot. - **Worth doing:** log your starting weight, a baseline appetite score, and your injection site. Baselines are the one thing you can’t backfill honestly. ## Week 2: the stack begins Your second dose lands on top of roughly half of the first — average levels are now ~50% higher than week one’s. Appetite effects often become noticeable here: smaller portions feel sufficient, snacking impulses thin out. GI side effects, if present, still cluster after dose day. Rotate your injection site — abdomen, thigh, or upper arm, a different spot than last week. ## Weeks 3–4: approaching the first plateau (the good kind) By week 4 you’re at ~90% of the starter dose’s steady state. Patterns become readable: maybe appetite dips hardest on days 2–4 and rebounds slightly before your next shot — that’s the sawtooth, and it’s worth seeing on a chart rather than doubting yourself. Constipation can appear around here as eating volume drops; fluids and fiber are the standard first response. **~90%** of steady state is reached after 4 weeks at a constant dose (≈ 4 half-lives for semaglutide). The first month is literally the climb. ## End of month: the first escalation decision Labeled schedules move to the next step after 4 weeks (0.25→0.5 mg semaglutide; 2.5→5 mg tirzepatide) — but the real-world decision is shared between you and your prescriber, and it leans heavily on tolerability. This is where a month of honest logs pays off: “nausea peaked at 4/10 the day after shots and faded by day three” is a decision-grade sentence. “It was okay, I think” is not. ## What’s actually worth tracking in month one Track | Why it matters later Weight (consistent rhythm) | The trend line every later conversation is built on. Doses + injection sites | Adherence math and healthy rotation. Appetite / food noise (0–10) | The earliest, most sensitive signal the medication is working. Side effects (0–10 severity) | Escalation decisions hinge on this curve. Protein + water | The two intake numbers that quietly fall when appetite drops. ## Red flags that skip the tracking and go straight to a clinician - Severe or persistent abdominal pain (with or without vomiting) - Repeated vomiting or signs of dehydration - Symptoms of an allergic reaction (swelling, breathing difficulty) - Severe hypoglycemia symptoms if you also use insulin or sulfonylureas These are label-level warnings, not app material. For everything milder, a good record turns month one from a blur into a baseline. **Start the record on day one** Weight, appetite, side effects, doses — GLPMate captures month one effortlessly (type it, confirm it), so every later decision has a baseline. [Get GLPMate free](/download) ## Sources 1. FDA Prescribing Information — Wegovy, Ozempic, Mounjaro, Zepbound ([Wegovy](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=215256), [Ozempic](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=209637), [Mounjaro](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=215866), [Zepbound](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=217806)) — starter doses, titration, common adverse reactions 2. [Wilding et al., NEJM 2021 (STEP 1) — semaglutide 2.4 mg](https://doi.org/10.1056/NEJMoa2032183) — GI side-effect timing: mostly mild-to-moderate, early, transient 3. [Jastreboff et al., NEJM 2022 (SURMOUNT-1) — tirzepatide](https://doi.org/10.1056/NEJMoa2206038) — adverse-event pattern during escalation This article is educational and is not medical advice, diagnosis or treatment. Medication decisions — including dose changes and what to do after a missed dose — belong with your prescriber. If you experience severe symptoms, seek medical care. ## Keep reading [Steady state, explained ](/learn/glp-1-steady-state-explained)[Side effects week by week ](/learn/glp-1-side-effects-week-by-week)[Missed a dose? The label rules ](/learn/missed-glp-1-dose-what-to-do) ## Start your GLP-1 journey with a companion that listens. Free to start. iOS & Android. 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