A standard NHS blood test measures about a dozen markers. A comprehensive private panel measures fifty or more. The difference is not trivial, it is the difference between knowing whether you are free of obvious disease and understanding how your body is actually functioning.
What a standard GP blood test includes: and what it doesn't
A routine full blood count and metabolic panel checks for anaemia, kidney function, liver enzymes, glucose and thyroid-stimulating hormone (TSH). It is a screening tool for significant pathology, excellent for identifying serious disease, limited for optimising function in people who feel unwell but are not clinically sick.
It typically does not include: vitamin D, B12 and folate; ferritin and iron studies (beyond simple serum iron); homocysteine; CRP or ESR (inflammation markers); magnesium; zinc; sex hormones (testosterone, oestradiol, FSH, LH, SHBG); adrenal hormones (cortisol, DHEA-S); IGF-1; or a full lipid sub-fractionation. These are the markers most relevant to energy, mood, skin quality, body composition, reproductive health and overall functional wellbeing.
Vitamin D: the marker most likely to change your health
Vitamin D deficiency affects an estimated 30–40% of UK adults in winter months. Mild deficiency is associated with fatigue, low mood, frequent infections, poor bone mineralisation and reduced insulin sensitivity. Severe deficiency is associated with osteomalacia, significantly increased infection susceptibility and impaired immune function.
The optimal range for vitamin D is contested, but most functional medicine practitioners target 100–150 nmol/L, significantly higher than the NHS 'adequate' threshold of 50 nmol/L. Achieving and maintaining optimal levels typically requires supplementation in the UK climate and, in cases of established deficiency, high-dose intramuscular D3 injection for rapid restoration.
B12: common, consequential, frequently missed
Vitamin B12 deficiency is common, particularly in those over 50 (reduced intrinsic factor production), those on plant-based diets (no dietary B12 source), those on metformin (which impairs B12 absorption) and those with any gastrointestinal condition affecting absorption. The symptoms, fatigue, brain fog, low mood, tingling extremities, poor memory, are non-specific and frequently attributed to other causes.
The standard serum B12 test measures total B12 including forms that are bound to transport proteins and not bioavailable. More sensitive markers include methylmalonic acid (MMA) and holotranscobalamin (active B12), which identify functional deficiency even when total serum B12 appears normal. Private panels that include these markers provide a more accurate picture of actual B12 status.
Hormonal panels: what changes and why it matters
A full hormonal panel, including testosterone, oestradiol, FSH, LH, SHBG, DHEA-S and cortisol, provides insight into the hormonal changes that profoundly affect energy, mood, body composition, libido, skin quality and cognitive function in both men and women from the mid-thirties onwards. These changes are gradual, normal and extremely consequential. Understanding them allows targeted intervention.
Testosterone decline in men is gradual (approximately 1% per year from age 30) but cumulative. The symptoms, reduced energy, reduced motivation, increased body fat, reduced muscle mass, low mood, reduced libido, develop gradually and are frequently attributed to 'just getting older' rather than to a measurable and addressable hormonal change. A comprehensive male hormonal panel establishes the baseline and guides appropriate intervention.
Inflammation markers: the silent risk factor
High-sensitivity CRP (hsCRP) and homocysteine are markers of chronic low-grade inflammation and endothelial dysfunction respectively, both strongly associated with cardiovascular disease risk, but also with accelerated ageing, cognitive decline and chronic fatigue. They are not included in standard NHS panels and are not part of standard cardiovascular risk calculators. They should be.
Blood testing and IV therapy: Testing before IV therapy transforms the protocol from generic to precise, identifying specific deficiencies and tailoring the infusion formulation to address your actual biochemical status. Comprehensive blood testing is available at Aesthetics Medispa with a follow-up consultation to interpret results and recommend next steps.
Treatments that work. Results you can see.
Every treatment at Aesthetics Medispa begins with a consultation.