retatrutide peptide side effects (LY3437943) — Dosing, Effects, FDA Status & Research | PeptIQ Retatrutide Side Effects Guide: 21

Dual agonists that activate both GLP-1 and GIP receptors tend to cause these side effects slightly more frequently than pure GLP-1 agonists

When to worry: No bowel movement for 5+ days despite interventions

In your pancreas, GIP strongly stimulates insulin secretion when blood glucose is elevated

262 It functions not only in peripheral tissues but also directly within the CNS, crossing the blood-brain barrier or being produced centrally to act on the brain

Last page review: 2026-04-01

In Phase 3 trials, nausea affected up to 42.4% of people, diarrhoea up to 34.1%, constipation up to 26.1%, and vomiting up to 25.3%, depending on the dose