Some patients experience fatigue, light-headedness, or dizziness in the first few weeks of starting GLP-1 weight loss medications or after a dose increase. These side effects are usually temporary and can often be managed with a few simple adjustments.
What Causes It
Lower food intake: Appetite suppression can lead to fewer calories, which may temporarily reduce energy levels.
Dehydration: GLP-1s may cause nausea or reduce thirst, increasing risk of dehydration.
Electrolyte imbalance: Especially if you’ve had vomiting or diarrhoea.
Lower blood sugar: Rare, but possible in some individuals due to delayed stomach emptying.
What You Can Do
Stay hydrated: Aim for 2–3L of water per day.
Add salt: A pinch of salt or electrolytes (especially if dizzy when standing) can help maintain blood pressure.
Eat enough: Ensure you're consuming enough calories, especially protein and nutrient-dense meals.
Avoid fasting or skipping meals, particularly early on.
Track your symptoms: Note when dizziness or fatigue occurs (e.g. morning, post-dose, post-meal).
When to See a Doctor
Dizziness that causes falls, fainting, or severe light-headedness
Fatigue that worsens over time or doesn’t improve after adjusting hydration and food intake
Symptoms accompanied by vomiting, diarrhoea, or palpitations
If in doubt, message or book a follow-up with your doctor via the portal. Fatigue and dizziness are common early on but usually settle as your body adjusts to treatment.