Monitoring Your Blood Sugar on GLP-1: A Practical Guide

GLP-1 receptor agonists work in part by stimulating insulin release when blood sugar rises and suppressing glucagon when it's already high. This mechanism means they're highly effective at improving blood sugar control — but it also means knowing how your glucose responds to food, exercise, and medication is genuinely useful information.

Who Should Be Monitoring Blood Sugar?

• Everyone with type 2 diabetes on GLP-1 therapy — your doctor will have a monitoring schedule
• People using GLP-1 for weight loss without diabetes — occasional monitoring can be informative
• Anyone experiencing hypoglycaemia symptoms: shakiness, sweating, confusion, rapid heartbeat
• Anyone combining GLP-1 with other diabetes medications like sulphonylureas or insulin

Understanding Your Blood Sugar Targets

General targets for adults with type 2 diabetes (always confirm with your doctor):

• Fasting (before breakfast): 4.0–7.0 mmol/L (72–126 mg/dL)
• 2 hours after meals: below 8.5–10.0 mmol/L (153–180 mg/dL)
• HbA1c target: typically below 7.0% for most adults, lower for younger patients

Continuous Glucose Monitors (CGMs): A Game-Changer

CGMs like the Libre 2 or Dexone provide real-time glucose readings every few minutes without finger pricks. Even a 2-week trial can be enormously informative: you'll see exactly how different meals spike your glucose, how exercise affects your levels, and whether your GLP-1 medication is working optimally. Many people are shocked to discover that supposedly 'healthy' foods cause large glucose spikes.

Practical Monitoring Tips

• Test fasting glucose first thing in the morning before eating or drinking anything except water
• Post-meal tests at 1 and 2 hours reveal which foods cause the largest spikes
• Log results with date, time, and what you ate — patterns emerge within a week
• If using GLP-1 for weight loss (no diabetes), a single fasting test every few days is sufficient
• Note how exercise affects glucose: even a 15-minute walk after meals significantly reduces post-meal spikes

Hypoglycaemia: When to Be Concerned

GLP-1 medications on their own rarely cause dangerously low blood sugar because they only stimulate insulin release when glucose is already elevated. However, if you're also taking insulin, sulphonylureas (like glipizide or glibenclamide), or are fasting aggressively, hypoglycaemia is a real risk. Symptoms include shakiness, sweating, confusion, and palpitations. Treat immediately with 15g of fast-acting carbohydrate (glucose tabs, orange juice, regular soda) and inform your prescriber.

How Your Numbers Should Improve on GLP-1

Most people on GLP-1 therapy see measurable improvement in fasting glucose within 4–8 weeks. HbA1c improvements of 1–2 percentage points are common over 3–6 months. If you're not seeing improvement despite adherence, discuss dose titration or combination therapy with your doctor.