Have you felt like something was off with your health, but your doctor said, “Everything looks normal” after a routine check-up? Maybe you’re struggling with low energy, stubborn digestive issues, or frustrating skin flare-ups, and you just know there’s more to the story.

That’s where functional lab tests come in. Instead of just looking at standard lab markers, functional tests take a deeper dive into your body’s biochemistry.

As a dietitian, I love using functional testing to help clients get to the root cause of their symptoms. It’s not about guessing, it’s understanding what’s really going on beneath the surface.

In today’s blog, I’ll be talking about the top 6 functional lab tests I recommend and why.

Want to learn more about me and why I love what I do? Check out my blog - Why I Do What I Do

What is Functional Lab Testing?

Functional lab tests are an innovative approach to healthcare that’s gaining attention in medical research.

Unlike conventional tests, functional labs aim to provide a comprehensive view of your health, by looking at the root causes of your issues.

Key aspects of functional testing include:

Preventative Focus: By identifying subtle imbalances, functional labs aim to detect potential health issues before they become bigger issues.
Root Cause Approach: Functional medicine testing aims to really get at the root cause of your symptoms. Struggling with acne? A gut health test might indicate that it’s stemming from an imbalance in your gut microbes.
Personalized Approach: These tests allow healthcare providers to really get the full picture of what’s going on with your health so they can help solve your unique problems.

Recent studies have shown promising results. One study showed that patients receiving functional medicine care reported improved quality of life compared to those receiving standard primary care.

Top 6 Functional Lab Tests I Recommend

As a registered dietitian, I love recommending functional tests to patients. It helps me develop a better treatment protocol and it helps you see what’s going on inside your body.

Here are the 6 I recommend the most:

Comprehensive Metabolic Panel Test
Lipid Panel Test
Hormone Tests
Gut Health Test: Gastrointestinal Microbial Assay Plus (GI-MAP)
Nutrigenomic Testing
Nutrient & Vitamin Deficiency Test

Now, let’s get into the details of each one!

Complete Metabolic Panel Test

A complete metabolic panel is a blood test that looks at 14 different markers. These markers measure:

How well your liver and kidneys are working
Your blood sugar levels
Your electrolyte and fluid balance
Protein levels in your blood

I recommend this test for several reasons:

To analyze how your diet is impacting your body.
To guide more personalized nutrition plans to improve overall health.
To spot and monitor conditions like diabetes.
To track progress if you’ve already begun making dietary changes.

Lipid Panel Test

A lipid panel is another blood test. It measures the different levels of fats (lipids) in your blood. These include:

Total cholesterol
LDL (“bad”) cholesterol
HDL (“good”) cholesterol
Triglycerides

These tests are important to understand your cardiovascular health. Dietary changes can significantly improve lipid levels for individuals.

Abnormal lipid levels can be a risk factor for cardiovascular disease, and I can use that information to assist with recommendations for a heart-healthy eating pattern.

Another reason these tests are important is for screening for potential health issues. They can help detect early signs so we can take a preventative approach to your health.

Hormone Tests

Hormone tests are becoming more and more popular to recommend as dietitians. These tests take an inside look at your hormones and can help us see how your hormones are impacting your overall health.

One of the most popular tests is the DUTCH (Dried Urine Test for Comprehensive Hormones) test. This measures key hormones like estrogen, progesterone, testosterone, and cortisol.

A couple of reasons I recommend this test are to look at underlying health issues like fatigue and mood swings and to address specific health conditions like PCOS and menstrual irregularities.

Gut Health Test: Gastrointestinal Microbial Assay Plus (GI-MAP)

This gut health test is a comprehensive stool test that looks at the microbial composition of your gut.

It looks at various microorganisms:

Bacteria
Viruses
Parasites
Fungi

Gut health is so important to your overall health, and this test does a great job of looking at any imbalances that might be contributing to digestive symptoms, autoimmune disorders, and chronic conditions.

I love to recommend this test to anyone struggling with digestive issues, fatigue, depression/anxiety, and more.

Nutrigenomic Testing

Nutrigenomic testing sounds complicated… but it’s pretty simple! It’s a type of genetic test that looks at your individual DNA to gain insights to how your body responds to different nutrients.

It’s often done through a simple cheek swab or blood sample.

I often recommend this test to help optimize your nutrient intake. For example, we can identify how your body absorbs different nutrients, which can help us decide if we need a certain supplement.

This field is still evolving, and more research is needed to fully understand gene-nutrient interactions.

Nutrient & Vitamin Deficiency Test

A nutrient and vitamin deficiency test helps assess whether you’re getting adequate levels of vitamins and minerals.

Deficiencies in key nutrients can lead to a variety of health issues:

Fatigue
Poor immune system
Lack of concentration
Long-term chronic conditions

Some of the key nutrients these tests look at include:

Vitamin D: Important for bone health, immune function, and mood regulation.
Vitamin B12 & Folate: Used for energy production, nerve function, and formation of red blood cells.
Iron & Ferritin: Low iron can lead to anemia, fatigue, and impaired brain function.
Magnesium, Zinc, & Other Minerals: Important for metabolism, muscle function, and overall cellular health.

I often recommend this test for individuals who often feel tired despite eating well, experience frequent illness, struggle with brain fog or poor concentration, and anyone with specific dietary patterns (ex: vegan, dairy free, gluten free).

Final Thoughts: Are Functional Lab Tests Right for You?

Functional lab testing provides data-driven insights into your overall health, helping to uncover imbalances and guide treatment protocols. Whether you’re looking to improve your energy, optimize digestion, balance hormones, or prevent long-term health issues, these tests can provide a lot of clarity.

There are so many out there, but the top 6 I recommend include:

Complete Metabolic Panel Test
Lipid Test
Hormone Tests
Gut Health Test: Gastrointestinal Microbial Assay Plus (GI-MAP)
Nutrigenomic Testing
Nutrient & Vitamin Deficiency Test

The specific functional tests I would recommend for you depend on your unique situation, your symptoms, and your goals. Usually, I just recommend 1-2 of these tests, not all 6!

Functional testing is a powerful tool, but it’s important to make sure you work with a qualified healthcare professional to interpret the results and create a care plan for you.

If you’re curious about functional lab testing and how it could support your health, I’d love to help! Book a consultation to explore which tests might be right for you and take the first step towards finally feeling your best!

Top 6 Functional Lab Tests I Recommend to Clients & Why