Diarrhoea is a common early side effect of GLP-1 weight loss medications. It typically occurs when your body is adjusting to the medication, especially after a dose increase.
What to Expect
Loose or watery stools
Increased urgency or frequency
Mild abdominal cramping or discomfort
These symptoms usually begin in the first few days after starting or increasing the dose, and often settle within 1–2 weeks.
Why It Happens
GLP-1 medications slow stomach emptying and affect how your gut moves. These changes can cause your digestion to speed up in some cases, resulting in diarrhoea.
How to Manage It
Stay hydrated: Drink plenty of water to replace lost fluids.
Avoid trigger foods: Cut back on high-fat, greasy, or spicy foods.
Eat simple meals: Choose bland foods like rice, bananas, toast, and potatoes.
Reduce caffeine and alcohol: Both can worsen diarrhoea.
Consider electrolytes: Oral rehydration salts or drinks like Hydralyte may help if diarrhoea is frequent.
When to Contact Your Doctor
Diarrhoea lasting more than 5 days
Signs of dehydration (dizziness, low urine output)
Severe abdominal pain or blood in the stool
Mild diarrhoea is expected and generally resolves as your body gets used to the medication. If symptoms persist or are severe, reach out to your doctor for advice.