Semaglutide Adverse Effects

## Common Adverse Effects of Semaglutide The most frequently reported adverse effects of semaglutide are gastrointestinal (GI) in nature, which are dose-dependent, typically emerge during dose escalation, and tend to diminish over time [1][2]. ### Incidence of Common Adverse Effects Based on pooled data from obesity trials (semaglutide 2.4 mg weekly vs. placebo) [7][9]: | Adverse Effect | Semaglutide 2.4 mg (%) | Placebo (%) | |----------------|------------------------|-------------| | Nausea | 44 | 16 | | Diarrhea | 30 | 16 | | Vomiting | 24 | 6 | | Constipation | 24 | 11 | | Abdominal pain | 20 | 10 | | Headache | 14 | 10 | | Fatigue | 11 | 5 | | Dyspepsia | 9 | 3 | | Dizziness | 8 | 4 | | Abdominal distension | 7 | 5 | | Eructation (burping) | 7 | <1 | | Flatulence | 6 | 4 | | Gastroenteritis | 6 | 4 | | Gastroesophageal reflux | 5 | 3 | | Gastritis | 4 | 1 | ### Clinical Characteristics - **Temporal pattern**: GI side effects occur most often during the **first 8 weeks** of treatment and during dose escalation [1][2]. - **Severity**: Typically **mild to moderate** in intensity [6][9]. - **Discontinuation rate**: Treatment discontinuation due to GI side effects occurs in approximately **4.5%** of patients (vs. 0.8% with placebo) [6]. - **Dropout rate in trials**: 4–8% across most clinical trials, primarily due to GI intolerance [1]. ### Management Strategies To mitigate GI intolerance, the following evidence-based approaches are recommended [2][4]: - **Dosing strategy**: Initiate at low doses (semaglutide 0.25 mg/week) with gradual titration every 4 weeks to the maximum tolerated dose [2]. - **Dietary modifications**: Eat slowly, choose smaller more frequent meals of bland low-fat foods (crackers, toast, rice); avoid greasy, fried, spicy, or highly sweetened foods [2][4]. - **Hydration**: Drink clear or ice-cold liquids in small, frequent sips [2][4]. - **Postural advice**: Do not lie down immediately after eating [2][4]. - **Symptomatic management**: Ginger or mint for nausea; increased fiber, hydration, and mobility for constipation; cautious rehydration for vomiting/diarrhea [2]. - **Pharmacological intervention**: In persistent cases, clinicians may consider domperidone or temporary dose reduction/interruption [2]. ### Additional Common Adverse Effects - **Hypoglycemia** (6% vs. 2% placebo): Particularly in patients with type 2 diabetes also taking insulin or sulfonylureas [4][7]. - **Injection site reactions**: Including local irritation [10]. - **Gallbladder-related events** (2.6% vs. 1.2% placebo): Mostly cholelithiasis [6]. - **Pancreatitis** (0.2% vs. 0% placebo) [6]. ### Ocular Adverse Events Emerging evidence from a 2025 systematic review and meta-analysis has identified an association between semaglutide and ocular adverse events, including worsening of diabetic retinopathy and nonarteritic anterior ischemic optic neuropathy (NAION) [5]. This represents a newer safety signal requiring further investigation. --- **Disclaimer**: This information is synthesized from retrieved literature and drug labeling for clinical reference. Clinicians should verify against the most current prescribing information and exercise individual patient judgment when managing adverse effects.