Considering a GLP-1 for Weight Loss or Diabetes? Don’t Skip These Important Tests

GLP-1 medications like Ozempic, Wegovy, Mounjaro, Trulicity, semaglutide, tirzepatide, and more have quickly become some of the most talked-about treatments for weight loss and type 2 diabetes. Originally developed for managing blood sugar in diabetes, these medications are now being prescribed more widely, including for people with PCOS, insulin resistance, and those looking for effective support with weight loss.

But before jumping in, there’s one important step that many people skip: a comprehensive blood test. Whether you’re starting a GLP-1 medication like Ozempic for weight loss, blood sugar control, or PCOS support, it's essential to understand your baseline health first. Blood testing helps identify how your body is functioning right now regarding blood sugar regulation, liver and kidney health, inflammation levels, and nutrient status. It can also flag any underlying issues that might affect how well you tolerate the medication or how quickly you see results.

Having this data upfront gives you something to track over time so you can see real-time, measurable progress rather than just relying on the number on the scale.

What Are GLP-1 Medications?

GLP-1 (short for glucagon-like peptide-1) receptor agonists work by mimicking a hormone that helps regulate blood sugar levels, slowing down digestion, and reducing appetite. In simple terms, they help your body respond better to insulin and make you feel full sooner. This combination makes them helpful not only for people with type 2 diabetes, but also for those struggling with losing weight, metabolic syndrome, or PCOS.

Are GLP-1's good for weight loss?

Yes, GLP-1 medications have been shown to support significant weight loss in many users, especially when paired with healthy eating and regular movement. They reduce appetite and help control cravings, which makes sticking to a lower-calorie diet more manageable.

Why Do You Need a Blood Test Before Starting a GLP-1?

Before starting any GLP-1 medication, it's a good idea to get a baseline blood test. This gives you and your doctor a clearer picture of where your health is starting from and can highlight any potential concerns that might affect how your body responds to the medication.

GLP-1 Pre-Treatment Health Check This is especially useful if you're considering taking a GLP-1 for weight loss but don’t have diabetes or insulin resistance diagnosed yet.

We recommend testing the following:

• Fasting glucose, insulin & HbA1c – These tell us how your body is handling blood sugar and insulin. They’re key for tracking changes over time.
• Lipid profile – GLP-1’s often improve cholesterol levels, and knowing your baseline helps show how much progress you’ve made over time.
• Liver function (ALT, AST, GGT, etc.) – GLP-1 meds are generally safe for the liver, but it’s good to check for underlying issues before beginning a new medication.
• Kidney function (eGFR, creatinine, etc.) – It’s important to measure this as these medications are cleared through the kidneys.
• Electrolytes – Especially helpful if you’ve been losing weight quickly or changing your diet, as this can throw off your electrolyte balance.

How Often Should You Test While Taking a GLP-1?

Once you’ve started a GLP-1, it’s important to keep an eye on how your body is responding. We recommend a full panel every 3 to 6 months to make sure things are heading in the right direction.

GLP-1 Follow-Up Health Check This includes all the same tests as the Pre-Treatment Check, plus:

• Vitamin B12 and folate – Long-term use of GLP-1s may lower absorption of these important nutrients.
• CRP (C-reactive protein) – A helpful marker for inflammation and cardiovascular risk, this often decreases with weight loss.
• Thyroid function – Thyroid changes can sometimes occur during weight loss or with metabolic shifts.

Why This Matters

If you’re investing in your health by starting a medication like semaglutide or tirzepatide, it makes sense to track your internal health too. Blood tests can catch imbalances early, show your progress over time, and give your prescribing doctor more to work with.

FAQ:

Do I need a blood test to get Ozempic? Not always, but it’s highly recommended, especially if you want to use it safely and monitor how your body responds.

Can Ozempic affect liver or kidney function? These medications are generally safe, but they are processed through the liver and kidneys, so it’s worth checking these organs regularly.

Is there a blood test to monitor semaglutide or tirzepatide levels? There’s no single “Ozempic test,” but regular blood panels (like the ones we offer) are used to track side effects, nutritional status, and overall metabolic health.

Can GLP-1 medications cause vitamin deficiencies? Some people may develop low B12 or folate over time. That’s why we include these in our ongoing monitoring panel.

What About Side Effects? Many people report nausea, constipation, diarrhoea, or bloating, especially in the first few weeks. These effects tend to settle down, but they can also be a sign that your gut microbiome is struggling to keep up.

That’s why we suggest pairing your blood testing with a Microbiome Check or a Complete Microbiome Mapping Check, especially if you’re experiencing digestive discomfort. Knowing the state of your gut bacteria can help guide probiotic, fibre, and dietary support to improve tolerance and avoid unnecessary symptoms.

If you're thinking about starting Ozempic, Mounjaro, or a similar GLP-1, or you’re already taking one and want to keep your health on track, check out our GLP-1 Pre-Treatment Health Check and GLP-1 Follow-Up Health Check testing panels. They’re specifically designed to support your journey with the data you need to make informed decisions, every step of the way.

Have questions or need help choosing the right test? We’re here to help. Reach out anytime.