Semaglutide Side Effects
Semaglutide (Ozempic / Wegovy) side effects are overwhelmingly gastrointestinal and concentrate during the dose-titration window. Most are mild-to-moderate and fade as the body adapts.
When they appear & how long they last
GI side effects peak in the days after each dose increase and typically ease within 1-2 weeks at a stable dose. The most volatile period is the first 8-16 weeks of titration. Effects that persist or worsen at a stable dose are worth a provider conversation.
Commonly reported Semaglutide side effects
The single most-reported effect, driven by slowed gastric emptying. Worst right after a dose increase.
Bowel-habit shifts in either direction as gut motility changes.
The intended mechanism - but can tip into under-eating if not watched.
Often tied to reduced calorie intake during rapid loss rather than the drug directly.
Mild redness or itching at the subcutaneous site.
Slowed emptying can push stomach contents upward.
When to contact your provider
- Severe, persistent abdominal pain (especially radiating to the back) - pancreatitis warning sign
- Signs of gallbladder problems - upper-right abdominal pain, fever, yellowing skin
- Vomiting that prevents keeping fluids down (dehydration risk)
- Rapid heart rate, palpitations, or vision changes
- Any signs of an allergic reaction (swelling, difficulty breathing)
Biomarkers worth tracking on Semaglutide
These catch issues early - before you feel them. Pull a baseline before you start, then re-check on the cadence noted below.
Confirms the metabolic response and watches for over-correction.
Tracks the glycemic improvement over 90-day windows.
Liver-enzyme baseline - hepatic fat often falls with weight loss.
How to actually track Semaglutide side effects
Log each dose against the day you took it, then note nausea / appetite / bowel changes alongside. Over a few weeks the pattern is obvious: most users see the GI curve flatten 7-10 days after each titration step. Pairing that with a fasting-insulin and HbA1c draw at baseline and 90 days shows whether the metabolic upside is landing.
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