*IV Ketamine, NR, and NAD+ have been used clinically off-label for decades. They are not FDA approved for the treatment of any psychiatric or pain condition. All medical treatments carry risks and benefits that you must discuss with a doctor at Clarus Health to learn if these therapies are right for you.
Most patients — and most doctors — believe that "normal" routine blood work means you're healthy. I used to believe that too, until I started providing second opinions for patients with fatigue, depression, brain fog, and chronic pain.
What I've found, again and again, is that patients are inadvertently gaslit. They're put on medications that carry side effects and may not even address the root cause of their problem — because the right chronic fatigue blood tests were never ordered, or the results were incorrectly interpreted as "normal," leaving the patient in the dark.
Here are the four most commonly missed opportunities when ordering and interpreting labs for chronic fatigue — and what you should be asking your doctor about.
Why "Normal" Lab Ranges Are Often Misleading
Before we get to the specific tests, it's worth understanding why normal ranges are so unreliable. Most people don't realize that reference ranges for a lab test can be established by measuring values in as few as 120 "healthy" individuals and picking a central value. That can't possibly capture the diversity of sex, race, age, and medical conditions across the population.
Is the normal range for a young pregnant white woman the same as for a 65-year-old African American man with diabetes? Research makes clear it often isn't — yet most labs use a single range for everyone. There are vanishingly few tests where we have more personalized ranges, and even then, a "normal" value doesn't mean it's healthy for that specific patient.
This matters most for patients with fatigue, brain fog, depression, and chronic pain — the very conditions where standard medicine has the highest failure rate.
1. Ferritin in Chronic Fatigue Syndrome
Ferritin is a critical biomarker of your body's iron stores and is essential for ensuring adequate oxygen delivery to your tissues. Without enough iron, you can develop anemia — a condition that can mimic depression, fatigue, and many other conditions.
The problem is that even without anemia, low iron stores can contribute to these symptoms. And most of my patients haven't had their ferritin checked at all, even though it's a relatively inexpensive test.
If you were lucky enough to have ferritin tested, the next problem is the reference range. The WHO considers a value below 15 ng/mL abnormal — but substantial evidence suggests the threshold for diagnosing iron deficiency should be set at double that number, particularly in women, who are disproportionately affected and more likely to be dismissed.
The numbers get even more specific depending on the condition:
- In restless leg syndrome, treatment is recommended for ferritin levels as high as 75 ng/mL
- In women with fatigue, iron supplementation improved symptoms at levels up to 50 ng/mL
If a patient comes to me with fatigue and depression, I want to rule out an iron deficiency before assuming they have a Prozac deficiency. This is one of the most common and most correctable oversights in standard medicine.
2. Testosterone and Depression, Low Energy
There is profound misunderstanding about testosterone in both men and women — starting with the assumption that it only affects sexual and reproductive function. In reality, testosterone influences mood, blood counts, bone density, energy, and overall sense of wellbeing. Bioidentical hormone replacement therapy addresses these imbalances directly.
Randomized clinical trials have demonstrated testosterone's benefits across a wide range of conditions:
- Depression in men: testosterone treatment is associated with alleviation of depressive symptoms
- Mood in women: transdermal testosterone therapy improves mood and cognitive symptoms in peri- and postmenopausal women
- Anemia: testosterone levels are significantly associated with anemia in older men
- Bone density: testosterone treatment improves volumetric bone density and strength in men with low levels
The challenge is that we don't have universally agreed-upon thresholds, and they vary from lab to lab. In men, some doctors treat under 250 ng/dL, others under 400, others under 500. Clinical trial data typically uses a baseline around 300 ng/dL — but lab reference ranges alone can't be the sole determinant of treatment.
In women, it's even more poorly understood. Most practitioners don't even consider testosterone in women, and there's a significant research gap around androgens in postmenopausal women. It is not currently possible to establish a universal reference range for premenopausal women — but that's not an excuse for not treating. When women finally do get treated, the results can be transformative.
The key takeaway: lab values don't tell the whole story. Symptoms must be evaluated alongside the numbers.
3. Vitamin D and Depression
Nearly every patient tells me their vitamin D was checked and it was "normal." And yet, when I look at the actual number, it usually isn't — at least not by the standards that matter for disease prevention.
Historically, levels above 20 ng/mL were considered normal. That threshold is increasingly insufficient, particularly in high-risk groups:
- Diabetes risk: In people at risk for developing type 2 diabetes — a significant proportion of the population — maintaining vitamin D levels above 50 ng/mL can reduce diabetes risk by 76%
- Depression: A traditional cutoff of 30 ng/mL may be insufficient to reduce depressive symptoms in some patients — relatively higher levels may be required
- Cancer: In individuals with normal BMI, supplementation to above 41 ng/mL can reduce the occurrence of advanced cancer — though the protective effect appears BMI-dependent
Ongoing studies are also examining optimal vitamin D levels in patients with chronic pain and fibromyalgia. The bottom line: vitamin D is not one-size-fits-all. Too high is dangerous, but too low — by the wrong standard — is also a risk. You need to discuss your specific number with a doctor who understands the nuance.
4. Cholesterol — Specifically Triglycerides and ApoB
Cholesterol labs matter because cardiovascular disease is the number one cause of death worldwide, and it is far more preventable than most people realize. The survival rate for a heart attack outside a hospital is under 10% — so prevention is everything. But standard cholesterol panels, and the cutoffs labs use, often miss the mark.
Take triglycerides. Most labs report anything below 150 mg/dL as normal. But that's far from optimal. Data on triglyceride levels and cardiovascular risk shows that the lower the number, the lower the risk — including levels under 80 mg/dL. The difference between 80 and 150 is nearly twofold in terms of cardiac event risk.
ApoB — apolipoprotein B — is similarly important and frequently overlooked. Optimal ApoB targets vary significantly based on a patient's health history, ranging from 65 to 100 mg/dL depending on risk factors. A blanket "normal" label on a standard lipid panel tells you very little.
This is why you should not simply accept "everything looks normal" as a final answer — especially if you're struggling with fatigue, brain fog, depression, or chronic pain. Ask specifically for the numbers. Ask what they mean for you.
What This Means If You Have Chronic Fatigue
Standard blood panels were designed to catch acute illness, not to optimize health or uncover the root causes of chronic symptoms. If you've been told your labs are normal but you still feel exhausted, foggy, or depressed, the problem may not be you — it may be what was measured, and how the results were interpreted.
At Clarus Health, we run advanced diagnostics across 150+ biomarkers to find what standard panels miss. Ferritin, free testosterone, 25-OH vitamin D at the right thresholds, ApoB, homocysteine, hs-CRP, fasting insulin, and genomic markers — the full picture, interpreted in the context of your symptoms, not just a reference range. This is the foundation of our approach to chronic fatigue, depression, and chronic pain — and why treatments like IV Ketamine, IV NAD+, and Stellate Ganglion Block work better when the underlying biology is addressed first.
References
- Interpreting Normal Values and Reference Ranges for Laboratory Tests — PubMed
- Reference intervals: an update — PubMed
- Defining Global Thresholds for Serum Ferritin — PMC
- The Management of Restless Legs Syndrome: An Updated Algorithm — Mayo Clinic Proceedings
- Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin — PMC
- Association of Testosterone Treatment With Alleviation of Depressive Symptoms in Men — JAMA Psychiatry
- Serum Androgen Levels in Women — JCEM
- Association of Testosterone Levels With Anemia in Older Men — JAMA Internal Medicine
- Efficacy and Safety of Testosterone Treatment in Men — Annals of Internal Medicine
- Clinical Practice Guideline for Systemic Testosterone for Hypoactive Sexual Desire Disorder in Women — Journal of Sexual Medicine
- Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes — PubMed
- The effect of vitamin D supplementation on primary depression — PMC
- Effect of Vitamin D3 Supplements on Development of Advanced Cancer — PMC
- The association between triglycerides and incident cardiovascular disease — Journal of Clinical Lipidology
- ESC/EAS Guidelines for the Management of Dyslipidaemias — European Atherosclerosis Society
