10/20/2026
If you are preparing for an IVF or IUI cycle, the trigger shot is one of the most important steps you need to understand. It is an injection of hCG given at a precise time during your cycle to signal your body to release mature eggs. In IVF it is typically given 36 hours before egg retrieval, and in IUI it is timed to coordinate with insemination. The injection itself is subcutaneous, goes just under the skin, and most patients describe it as a brief sting. Mild bloating or tenderness afterward is normal, but if you experience severe pain contact your care team right away.