Semaglutide Side Effects Timeline: What to Expect and When

Week-by-Week Side Effects Timeline

Most Common Side Effects

Nausea (30–44% of users)

The most common side effect. Usually peaks in the first 2–4 weeks at each new dose and then improves. Eating small, low-fat meals helps significantly. Avoid lying down right after eating.

Constipation (24% of users)

GLP-1 medications slow digestion — constipation is common and underreported. Increase fiber, water, and movement. Magnesium glycinate (check with your prescriber) is often helpful.

Diarrhea or loose stools

Less common than constipation but does occur, especially at dose initiation. Usually resolves within a week or two.

Fatigue

Common in the first few weeks, especially if eating significantly less. Make sure you are getting adequate protein and calories despite reduced appetite.

Burping or sulfur burps

A frequently reported and under-discussed side effect. Caused by slowed gastric emptying. Avoiding fatty or high-protein foods before bed can help.

Side Effects That Do Not Go Away

If nausea or GI symptoms are severe and not improving after 4 weeks at the same dose, contact your prescriber. Options include staying at the current dose longer before escalating, trying a different injection time, or adjusting dietary habits.

See also: Semaglutide Dosage Chart · Dosing Schedule