Helvy
Immune & Inflammation
In the UK, the standard clinical (NHS) reference range for Lymphocyte Percentage is 20-45 %, with 30-45 % considered the performance-optimised range. A result within these ranges suggests typical status; only a qualified clinician can interpret an individual reading.
Lymphocyte percentage is the share of white blood cells that are lymphocytes — the T-cells, B-cells, and natural killer cells that drive adaptive immunity. It is reported alongside absolute lymphocyte count on a standard full blood count. In the Levine PhenoAge composite, a declining lymphocyte percentage is one of the strongest signals of immunosenescence — the age-related erosion of immune function.
Optimal range · UK
30-45 %
Performance-optimised band · clinical (NHS) range 20-45 %
Reference ranges for Lymphocyte %, not a personal result. Any individual reading should be interpreted by a qualified clinician.
Optimal ranges
| Range | Value |
|---|---|
| Clinical (NHS) reference range | 20-45 % |
| Performance-optimised range | 30-45 % |
The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best. A result in either range suggests typical status and is not a diagnosis; any individual reading should be interpreted by a qualified clinician.
Why it matters
Lymphocyte percentage falls naturally with age as the thymus involutes and naive T-cell production slows. A higher-than-typical-for-age percentage suggests a younger immune profile, better vaccine response, and lower infection risk. Persistently low lymphocyte percentage (often paired with high neutrophil percentage) is a marker of chronic stress, chronic inflammation, or undiagnosed infection. A neutrophil-to-lymphocyte ratio above 3 is a recognised inflammation signal independent of CRP.
Symptoms
Low / Deficiency
High / Excess
Dietary sources
Supplementation
Address the upstream drivers: chronic sleep debt, sustained psychological stress, and gut inflammation all suppress lymphocyte function. Zinc (15-30 mg with copper), vitamin D (to a 25-OH level above 100 nmol/L), and adequate protein intake support normal lymphocyte production. Direct supplementation is not appropriate.
Testing
Lymphocyte % is measured from a blood sample. With Helvy, that means a finger-prick kit taken at home and posted to a UKAS-accredited UK laboratory, with results in around 5 days, reviewed by a qualified clinician. Your result is reported against both the clinical range (20-45 %) and the performance-optimal range (30-45 %), so you can see not just whether you are “normal” but whether you are optimal. If you make a change, retest after 8-12 weeks to confirm it worked.
Research
An epigenetic biomarker of aging for lifespan and healthspan
Levine ME, Lu AT, Quach A, et al.
Aging (Albany NY) (2018)
DOI: 10.18632/aging.101414Related biomarkers
Related guides
This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.
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