Brain Fog Blood Test

11 Biomarkers | Venous Blood Test | CE-marked | UKAS-accredited | Doctor-reviewed results with personalised interpretation.

A focused blood test checking markers linked to brain fog, poor concentration, mental fatigue and low energy, including thyroid hormones, iron status, vitamin B12, folate and vitamin D. Designed for people who feel mentally cloudy, forgetful or unable to focus, this test gives clear, clinically reviewed insight into common blood markers that may affect energy and cognitive wellbeing.

Results are typically available within 2 working days from when your sample reaches the laboratory, excluding weekends and bank holidays.

£99.00

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Choose your sample collection method: Book a venous draw at our Livingston clinic Book a venous draw at home with a nurse +£63 Self-arrange a professional sample collection Partner clinic visit + £35.00 Finger Prick

Active Vitamin B12
Folate
Vitamin D

Ferritin
Iron
Total Iron Binding Capacity
Unsaturated Iron Binding Capacity
Transferrin Saturation

Fasting required 8–12 h before the test (water only) recommended for glucose, cholesterol/triglyceride accuracy
Sample timing: between 7:00 AM – 10:00 AM
Stay hydrated; avoid strenuous exercise, heavy meals, and supplements (iron, B12, multivitamins, biotin) for 48 hours prior
Continue prescribed medications unless otherwise directed

Frequently asked questions

It is for adults struggling with poor concentration, forgetfulness or a persistent sense of mental cloudiness. It examines the common physiological contributors, including thyroid function, vitamin B12 and folate, vitamin D, blood sugar regulation and inflammation.

Brain fog is a description of symptoms rather than a diagnosis, but the symptoms are real and frequently have measurable causes. An underactive thyroid, B12 deficiency, anaemia and unstable blood sugar are all recognised contributors that this panel can identify.

Yes, if blood sugar markers are included for you. Please fast for 10 to 12 hours and drink only water so that glucose readings reflect your baseline rather than your last meal.

It can. Supplements and recent B12 injections raise the measured level, which may mask an underlying absorption problem. Tell us what you take when booking, and where possible stop oral B12 for two weeks beforehand unless it has been prescribed for a diagnosed deficiency.

Normal results exclude the common physical causes, which is valuable information. Sleep quality, stress, perimenopause, long COVID and mental health all affect cognition, and your report will suggest where to look next.