GLP-1 Side Effects Management Guide (2026): Nausea, GI, Fatigue

Common side effects by dose

Nausea management

• Smaller frequent meals: 5-6 small meals instead of 3 large
• Protein-first eating: protein triggers less nausea than fats and refined carbs
• Avoid high-fat foods: they delay gastric emptying further
• Ginger: 1g/day in capsules or tea; meta-analysis shows efficacy comparable to ondansetron for mild nausea
• B6 (pyridoxine): 25-50mg/day; pregnancy-validated antinausea
• Prescription options: ondansetron 4-8mg PRN; promethazine 25mg PRN — discuss with prescriber

Constipation management

• Water intake target: 2.5-3L/day
• Fiber: 25-35g/day (psyllium husk if not getting enough)
• Magnesium citrate 200-400mg/day at bedtime
• Stool softener (docusate 100mg BID) if hard stool
• Stimulant laxative (senna or bisacodyl) only short-term

When to hold or downtitrate

• Hold escalation: if at any titration step, GI symptoms prevent normal eating/hydration for >5 days
• Hold same dose: extend the step by 4 more weeks before next escalation
• Downtitrate: back to previous step if symptoms persist on hold
• Skip a week: if missed dose by >5 days, skip the dose entirely and resume next week

Red flags requiring clinician review

• Severe persistent abdominal pain (especially radiating to back) — rule out pancreatitis (lipase, amylase)
• Persistent vomiting >48h with inability to keep fluids down — dehydration risk
• Right upper quadrant pain + nausea after fatty meals — gallstones
• Mental status changes in T2D patients — hypoglycemia risk
• Severe constipation with no bowel movement >5 days
• Visual changes in retinopathy-prone patients (rare but reported)

Contraindications (do not use)

• Personal or family history of medullary thyroid carcinoma (MTC)
• Multiple endocrine neoplasia syndrome type 2 (MEN 2)
• Hypersensitivity to semaglutide/tirzepatide
• Pregnancy or breastfeeding (Category C)