What an Organic Acids test reveals that bloodwork can’t

The Organic Acids Test (OAT) is one of the most powerful tools in functional medicine, and one of the worst-explained. Patients who order it often come back with a seventeen-page report and a vague sense that “some markers were elevated.” What the test is actually measuring is the chemistry of how the body is making, using, and clearing energy, in real time, in urine. Once you know what you are looking at, the report becomes a map.

What “organic acids” actually are

When the body burns fuel to make energy, breaks down neurotransmitters, processes B vitamins, or detoxifies, it produces small intermediate molecules — organic acids — that get filtered into urine. The level of each one tells you whether that step in the pathway is running smoothly, backed up, or starved of a cofactor. It is the closest thing to live telemetry of the body’s metabolism that we can run in an outpatient setting.

Bloodwork is a snapshot of what is in circulation. The OAT is a snapshot of what the body is doing. They answer different questions, and most of the chronic patterns I see live on the OAT side of that line.

The five blocks of the panel I look at first

• Mitochondrial markers— the citric acid cycle intermediates (citrate, cis-aconitate, isocitrate, alpha-ketoglutarate, succinate, fumarate, malate). When these are elevated as a pattern, the mitochondria are not completing the cycle. That is the biochemistry behind the patient who says “I used to be able to keep going.”
• Fatty acid oxidation— adipate, suberate, ethylmalonate. Elevations here mean the body cannot burn fat efficiently for fuel, which presents as energy crashes, exercise intolerance, and weight that doesn’t move with caloric restriction.
• Neurotransmitter byproducts — vanilmandelate (norepinephrine), homovanillate (dopamine), 5-hydroxyindoleacetate (serotonin), quinolinate. The pattern here predicts mood, focus, motivation, and sleep more accurately than any patient self-report.
• Microbial overgrowth markers — arabinose, tartaric acid, beta-keto glutarate, and several Clostridia species byproducts. These are how the OAT picks up yeast and dysbiosis from the urine without a stool sample. Notably, this is also where we see the chemistry of a child whose behavior changes correlate with their gut.
• Methylation and B-vitamin functional need— methylmalonic acid (B12), xanthurenate (B6), formiminoglutamate (folate), pyroglutamate (glutathione). This block tells you whether the patient’s vitamins are being used, not just whether they are present in serum.

Three patient stories the OAT actually solves

The fatigued executive. Bloodwork normal, sleep optimized, exercise consistent — and still tired. OAT shows a flat citric acid cycle, low fatty-acid oxidation markers, and elevated quinolinate (a neurotoxic tryptophan metabolite). The mitochondria are running on fumes. Plan: targeted CoQ10, carnitine, B-vitamins (especially B2 and B3), magnesium, and a workup for the chronic low-grade inflammation that is driving quinolinate. Six weeks in, the patient stops needing the second coffee.

The child who can’t focus. Standard pediatric workup unrevealing. OAT shows elevated arabinose (Candida overgrowth), elevated HPHPA (a Clostridium byproduct that disrupts dopamine), and low homovanillate (low dopamine output). Plan: address the gut, support dopamine cofactors (B6, magnesium, tyrosine), and watch attention rebuild over months. The behavior was the chemistry talking.

The post-viral patient. Three months out from a respiratory illness, still not back to baseline. OAT shows mitochondrial markers elevated, fatty-acid oxidation suppressed, and quinolinate high — a clean fingerprint of post-viral mitochondrial dysfunction. Plan: paced rehabilitation, mitochondrial cofactors, antioxidants, and the discipline to not over-train into the recovery. We re-test in three months.

What an OAT is — and isn’t — going to do for you

Right fit: chronic fatigue, brain fog, mood and focus issues, suspected mitochondrial dysfunction, chronic candida or dysbiosis, post-viral recovery, ADHD-pattern presentations in children and adults, autism support, unexplained muscle aches or exercise intolerance, methylation work where the patient needs to know what their B-vitamins are actually doing.

Not the right test: for acute illness, for ruling out structural disease, or as a first-line screen in a healthy patient with no complaints. The OAT is a precision tool. It rewards a specific clinical question, and it overwhelms a patient who orders it without one.

How I read the report with patients

We do not read it marker by marker. We read it as patterns. A single elevated value is rarely the story; the shape of how the elevations cluster is. Mitochondrial block elevated together with low fatty-acid oxidation is one story. Microbial markers elevated together with neurotransmitter dysregulation is a different story. The skill is in seeing which pattern the report is telling, and then choosing the smallest number of interventions that move the most levers at once.

The OAT does not tell you what is wrong. It tells you what your body is doing about it. That is what makes it the most clinically useful test on the shelf.

If your symptoms are functional rather than structural — energy, focus, mood, recovery, the day-to-day quality of how you actually feel — and bloodwork has not given you an answer, this is the panel I would order next.

The journal is written by Dr. Nazzar from the practice. Articles reflect clinical observation and current research, not personalized medical advice. To explore your own case, schedule a consultation.