What are the most common side effects people report when starting a GLP-1 medication?

Gastrointestinal effects are by far the most commonly reported: nausea, constipation, diarrhea, and occasionally vomiting, especially during dose increases. Less commonly, people report fatigue, headaches, or mild dizziness. Most of these tend to be most noticeable in the first weeks of a new dose and settle down as the body adjusts, though how much and how long varies a lot from person to person. References: https://obesitycanada.ca/healthcare-professionals/adult-clinical-practice-guideline/