How to Read a Blood Panel for Hormone Optimisation

Research disclaimer: This article is for informational purposes only and does not constitute medical advice. Blood test interpretation should always be conducted in the context of your clinical presentation by a qualified healthcare professional. Reference ranges vary between laboratories.

Why Blood Panels Matter for Optimisation

Subjective health — how you feel, your energy, your sleep quality, your body composition — is real data. But it is incomplete data. Hormone levels, inflammatory markers, and metabolic indicators can shift meaningfully before symptoms become noticeable. For anyone taking a proactive approach to health, a periodic blood panel provides an objective baseline against which to measure change.

This guide covers the markers most relevant to hormone optimisation and metabolic health. It is not a guide to diagnosing pathology — that is a task for a clinician — but to understanding what you are looking at when you receive your results.

Understanding Reference Ranges

Reference ranges on blood panels represent the statistical range within which 95% of a healthy population falls. This means by definition, 5% of healthy people will have results outside the "normal" range at any given time.

More importantly, reference ranges are often designed to detect disease, not to indicate optimal function. A testosterone level at the bottom of the reference range is technically "normal" but may be associated with symptoms and functional compromise that a person optimising for performance or wellbeing would find meaningful.

Learning to read ranges in the context of your own trends — not just single-point values — is key. A result that has moved from the upper quartile to the lower quartile over two years is significant even if it remains "in range."

Key Hormone Markers

Testosterone (Total and Free)

Total testosterone measures all testosterone in the blood, including protein-bound forms. Free testosterone — typically 1–3% of total — represents the biologically active fraction.

• Men: Total testosterone reference ranges typically span 270–1070 ng/dL (varies by lab). Functional optimisation discussions often centre on the upper-middle range (600–900 ng/dL). Free testosterone below 50 pg/mL in adult men is frequently associated with symptomatic hypogonadism.
• Women: Total testosterone is lower (15–70 ng/dL typical) but equally important for libido, energy, and body composition.

Always check SHBG (sex hormone binding globulin) alongside total testosterone — high SHBG binds testosterone and reduces free fraction, meaning total levels can appear adequate while free levels are suboptimal.

Oestradiol (E2)

Relevant for both men and women. In men, oestradiol (produced by aromatisation of testosterone) has important roles in bone density, cardiovascular health, and libido — but elevated levels are associated with gynecomastia and water retention. Target range for optimised men is often 20–30 pg/mL.

LH and FSH

Luteinising hormone (LH) and follicle-stimulating hormone (FSH) are pituitary hormones that drive testicular/ovarian hormone production. Low LH and FSH in the context of low testosterone suggests secondary (hypothalamic/pituitary) hypogonadism; normal or high LH/FSH with low testosterone suggests primary gonadal failure.

Thyroid Panel: TSH, Free T3, Free T4

TSH is the pituitary signal that drives thyroid hormone production. An elevated TSH suggests the pituitary is working hard to stimulate an underperforming thyroid. But TSH alone is insufficient: Free T3 is the biologically active thyroid hormone and may be depressed even when TSH appears normal.

A full thyroid panel (TSH + Free T3 + Free T4 + Reverse T3 + thyroid antibodies) is more informative than TSH alone, particularly when fatigue, body temperature, or metabolic sluggishness are concerns.

DHEA-S

Dehydroepiandrosterone sulphate (DHEA-S) is a precursor to both testosterone and oestrogen, produced by the adrenal glands. Levels decline markedly with age. Low DHEA-S is associated with fatigue, reduced libido, and immune function changes in older adults. Because DHEA-S is produced by the same adrenal axis that regulates cortisol, chronic HPA overactivation from stress can suppress DHEA-S alongside raising cortisol — a pattern that ashwagandha's adaptogenic effects on the HPA axis are specifically researched to address, with multiple RCTs showing meaningful cortisol reduction after 8 weeks of supplementation.

Metabolic Markers

Fasting Insulin and HOMA-IR

Fasting glucose alone underestimates insulin resistance. Measuring fasting insulin simultaneously allows calculation of HOMA-IR (Homeostatic Model Assessment of Insulin Resistance): (fasting insulin × fasting glucose) / 405.

HOMA-IR above 2.0 suggests developing insulin resistance; above 3.0 is associated with metabolic syndrome. This marker is often abnormal years before fasting glucose rises — making it a valuable early warning. The link between insulin resistance and hormone dysregulation is bidirectional and well-established.

This aligns with research into therapies targeting the metabolic axis, such as GLP-1 agonists like semaglutide and tirzepatide.

HbA1c

Glycated haemoglobin reflects average blood glucose over approximately three months. An HbA1c below 5.4% is generally associated with optimal metabolic function; 5.7–6.4% indicates prediabetes.

Lipids and ApoB

Standard lipid panels (total cholesterol, LDL, HDL, triglycerides) are useful but incomplete. ApoB — apolipoprotein B — measures the number of atherogenic lipoprotein particles directly, which is more predictive of cardiovascular risk than LDL cholesterol alone. An ApoB below 80 mg/dL is a commonly cited optimisation target.

Inflammation Markers

hsCRP

High-sensitivity C-reactive protein is a sensitive marker of systemic inflammation. Below 1 mg/L is optimal; 1–3 mg/L is moderate risk; above 3 mg/L is high risk. Chronically elevated hsCRP correlates with accelerated cellular ageing, cardiovascular risk, and metabolic dysfunction.

Homocysteine

Elevated homocysteine is associated with cardiovascular disease risk and poor methylation. Above 15 μmol/L warrants investigation into B vitamin status (B12, folate, B6).

A Relevant Research Reference

For a comprehensive review of biomarker strategies in longevity medicine, this 2023 paper is a useful resource: Biomarkers of ageing and frailty.

Practical Tips for Getting Value from Blood Tests

1. Fast for 10–12 hours before a metabolic panel to get accurate fasting insulin and glucose
2. Test at consistent times — testosterone peaks in the morning; always draw at the same time of day for repeat tests
3. Track longitudinally — a spreadsheet of results over 12–24 months reveals trends that single snapshots miss
4. Know your lab's specific ranges — reference ranges can vary by 10–20% between laboratories

Summary

Blood panels are a powerful tool when interpreted correctly. The key shift is from binary "normal/abnormal" thinking to understanding trends, individual context, and the difference between population-normal and personally optimal. Paired with understanding of how peptides and longevity interventions interact with these markers — including what NAD+ research suggests about cellular function — blood panels become a foundation for informed health decision-making. One commonly overlooked addition is RBC (red blood cell) magnesium: standard serum magnesium can appear normal while intracellular stores are depleted, making RBC magnesium a more accurate test for the suboptimal status linked to sleep disruption and anxiety. What each magnesium test actually measures — and why it matters is covered in detail in the magnesium guide.