Functional lab tests consist of serum (blood), saliva, urine, and/or stool analyses and provide insight into the body’s physiological status. Through these tests, we gain an appreciation for which biochemical processes are optimized and which ones may need more attention. The results often evoke meaningful behavior change—especially when we are on the fence about something.

In Functional Medicine (FM), our aim is to uncover the root causes of disease, understand how to prevent imbalances, and learn how to return the body to homeostasis. For example, if someone wants to know whether they would benefit from magnesium or omega-3 fatty acid supplementation, rather than guessing, it is best to test levels (such as the omega-3 index for essential fatty acids). This ensures that the dosage they are taking is truly therapeutic and, most importantly, safe.

What many people, both patients and practitioners, do not realize is that the dosage listed on a supplement label usually refers to the Recommended Dietary Allowance (RDA) or the Recommended Intake Dose (RID), both of which are scientifically formulated metrics developed by national health authorities (RIDs are used when RDAs are unavailable).

In FM, we often recommend supplement dosages above the RDA to achieve therapeutic benefit. While these therapies differ between practices, they should always fall within evidence-based guidelines and an appropriate standard of care.

Integrative practitioners often use functional medicine testing because they blend conventional practice with complementary modalities such as Traditional Chinese Medicine, Functional Medicine, and Acupuncture.

Conventional practitioners working strictly within the allopathic model generally do not order functional labs. This is largely because:

• Many functional labs are still in an early or evolving stage.

• Some tests provide experimental or emerging data. Recall the Human Genome Project and how we are now witnessing its long-term outcomes.

• Widespread adoption requires large bodies of research and long-term data.

• Insurance coverage often lags behind scientific progress.

That said, one functional lab test gaining traction in conventional medicine is the advanced lipid panel.

Unlike a standard cholesterol panel, it evaluates lipoprotein particle size—for example, small LDL particles (more atherogenic, more likely to contribute to plaque formation, heart attack, and stroke) versus large, buoyant LDL particles (considered “safer” from a cardiovascular risk perspective).

Many of my clients with elevated cholesterol and a family history of cardiovascular disease benefit greatly from advanced lipid testing. It helps them decide whether adopting a strict vegan lifestyle is worth the effort or whether a statin should be considered. These decisions are case-by-case, but functional labs provide clarity.

Functional and conventional tests are not mutually exclusive—each provides information that contributes to a whole-person approach.

I encourage clients to maintain their annual physicals with their primary care providers and then integrate functional labs as needed to fill in the gaps, gain deeper insight, improve wellbeing, reduce risk, and address unresolved symptoms.

If any of the following questions resonate with you, there is likely a functional lab test that can help:

• Should I be taking a probiotic, prebiotic, or synbiotic?

• My bowel habits have changed and I’m seeing undigested food—what does this mean?

• My energy is low. Am I anemic? Low in stomach acid? Is it hormonal?

• My doctor says my thyroid is “normal,” but could it work more efficiently?

• I rely on caffeine, but coffee makes me jittery and anxious—why?

• Why do cigarette smoke and perfumes suddenly make me nauseous (and if I am female, I’m not pregnant)?

• I used to lose weight easily, but my belly fat now won’t budge. Is this insulin resistance?

• No matter what I eat, I cannot gain weight or muscle mass.

• My hair is thinning and my nails are brittle despite supplements.

• Alzheimer’s runs in my family—am I destined for cognitive decline?

• I’m bloated no matter what I eat. My doctor ruled out everything.

• My periods are painful and disrupting daily life—but I want to conceive soon.

• I’m pre-diabetic despite avoiding sugar—what’s going on?

• My blood pressure is borderline high—can I avoid medication?

• How can I prevent my autoimmune condition from worsening?

Clients often come to me at a crossroads. They don’t know if medication is the answer or if deeper, targeted lifestyle changes could turn things around. Many have done the conventional “song and dance” with limited relief.

We are entering a time where simply avoiding the emergency room is not an adequate measure of health.

If you want insights into your longevity and wellbeing, there is a functional lab that can guide you.

Like most certified functional medicine practitioners, I begin with the gut. I often recommend a comprehensive stool test—especially when chronic symptoms are present or if it has been more than three years since the last test and new concerns have emerged.

Stool tests are highly informative; they reveal where to focus efforts and whether inflammation is present. If inflammation is identified, we begin by “putting out the fire.”