Current promotion
Blood Tests for Post-COVID Fatigue, Brain Fog & Low Energy
Lab panels that measure the inflammation, immune, hormone, and nutrient markers most often reviewed when energy and focus don't rebound after COVID-19.
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Eight panels from $99 to $595 after the 20% promotion (regular $126.95–$789.95); promotional pricing at time of writing.
At a glance
Blood testing for post-COVID fatigue and brain fog measures markers, inflammation (CRP, ESR, cytokines), EBV reactivation, hormones, nutrients, and organ function, that are commonly reviewed when energy and concentration don't recover after a COVID-19 infection. These panels are for adults still experiencing exhaustion, poor concentration, unrefreshing sleep, or mood changes weeks to months after their acute illness. Results are designed to be tracked over time and reviewed with your doctor.
Best suited for
- Adults whose energy has not returned weeks or months after a COVID-19 infection
- People experiencing brain fog, trouble concentrating, memory lapses, or mental exhaustion, since their infection
- Those with unrefreshing sleep, mood changes, or reduced exercise tolerance after COVID-19
- Anyone who wants objective lab data to bring to a doctor's visit about post-viral fatigue
What's included
Post COVID-19 Inflammation-induced EBV Reactivation (Long COVID - EBV)
12 tests, 94 biomarkers, immune and reactivation markers
Post COVID-19 Mini Panel (Long COVID)
5 tests, 32 biomarkers, entry-level screen
Post COVID-19 Expanded Panel (Long COVID)
10 tests, 90 biomarkers
Post COVID-19 Comprehensive Panel (Long COVID)
19 tests, 101 biomarkers, broadest evaluation
Post COVID-19 Cytokine Testing (Long COVID)
1 test, inflammatory cytokine marker
Post COVID-19 Cardiac and Pulmonary Panel (Long COVID)
2 tests, 2 biomarkers
Post COVID-19 Coagulation Panel (Long COVID)
2 tests, D-dimer and fibrinogen activity
Post COVID-19 Rheumatological Panel (Long COVID)
5 tests, 7 biomarkers
Key biomarker ranges
Commonly used adult reference ranges for markers this panel measures, labs vary, so always interpret results against your lab's stated ranges and with your doctor.
Commonly used cutoffs: under 1 mg/L low, 1–3 mg/L average, over 3 mg/L high; acute illness or injury can spike results, so retesting confirms a trend.
| Zone | Range |
|---|---|
| Low | 0–1 mg/L |
| Average | 1–3 mg/L |
| High | 3–10 mg/L |
For eGFR, lower is worse: 90+ is consistent with full kidney function, while sustained values below 60 are the commonly used threshold of concern.
| Zone | Range |
|---|---|
| Kidney failure range | 0–15 mL/min/1.73m² |
| Reduced | 15–60 mL/min/1.73m² |
| Mildly reduced | 60–90 mL/min/1.73m² |
| Optimal | 90–120 mL/min/1.73m² |
The importance of testing
Fatigue and brain fog are among the most common symptoms reported after a COVID-19 infection, and they rarely come with an obvious explanation. Lab testing turns a vague feeling of being drained into specific, trackable numbers: inflammatory markers such as CRP, ESR, and cytokines characterize lingering inflammation that has been studied in connection with persistent post-viral symptoms.
A dedicated panel measures markers associated with Epstein-Barr virus (EBV) reactivation, an area researchers have examined in people with ongoing fatigue after COVID-19. Hormonal and metabolic checks look at the endocrine markers associated with symptoms like tiredness, weight fluctuation, and mood swings, while a nutritional assessment screens for deficiencies in nutrients relevant to energy and recovery.
Because no single value explains post-COVID fatigue, the value is in the pattern: establish a baseline across inflammation, immune, hormone, and nutrient markers, then retest as symptoms evolve. Bring the results to your physician or a post-COVID clinic, flagged values give the conversation a concrete starting point and help identify which findings warrant follow-up.
Promo code
ULTA0BC3Save 20% with code ULTA0BC3, current promotion; confirm final pricing on the partner page.
Ready to get your numbers? Order online, visit a nearby draw site, and receive private results to review with your doctor.
Order NowFrequently asked questions
What blood tests help investigate fatigue after COVID-19?
Markers commonly reviewed for post-COVID fatigue include inflammatory markers (CRP, ESR, cytokines), EBV-reactivation markers, hormone and metabolic panels, and nutrient assessments. These panels bundle those marker groups so you can measure them in one order and track how they change as your recovery progresses.
Can a blood test tell me whether my brain fog is from Long COVID?
No, no lab test can confirm brain fog or Long COVID. What testing can do is measure markers associated with inflammation, immune activation, hormonal shifts, and nutrient status, so you and your doctor can see whether any measurable factor is out of range and worth addressing.
Which panel is best for post-COVID fatigue and brain fog?
The 12-test Inflammation-induced EBV Reactivation panel (94 biomarkers) is the most fatigue-focused option, since it covers immune and reactivation markers alongside broader labs. For a lower-cost baseline, the 5-test Mini Panel ($99 with the current promotion) is a reasonable start, while the 19-test Comprehensive panel is the widest single evaluation.
Do I need a doctor's order to get these tests?
No doctor's visit is required, these panels can be ordered directly online, with sample collection at a local lab. You receive the results yourself and can share them with your physician or a post-COVID clinic for interpretation.
Can I order this testing in every US state?
No, direct-to-consumer lab testing is restricted or prohibited in New York, New Jersey, and Rhode Island, so residents of those states may be blocked at the partner's checkout. Most other US states allow online ordering with collection at a nearby patient service center.
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