Fatigue on a GLP-1 does not usually mean the medication is failing. It usually means your intake of a handful of key nutrients has quietly dropped below where it needs to be.
The four suspects
1. B-vitamins
B1, B2, B3, B6, B12, and folate are cofactors in the machinery that turns food into ATP. Eat less food, and you may get less of these.
2. Iron (if you are premenopausal)
Iron is highly individual and can be harmful in excess, so it is not something to add blindly. If your energy has crashed and you are premenopausal, ask your doctor to check ferritin, not just hemoglobin.
3. Sodium, potassium, and magnesium
You are eating less food, which means less salt and fewer mineral-rich foods. Low sodium and low potassium show up as fatigue, dizziness, and headaches, long before they look dramatic on a lab report.