The Male Hormone Panel: Testosterone, Oestradiol, SHBG and More
A morning draw, SHBG alongside total testosterone, calculated rather than direct free testosterone, and LH and FSH to locate the cause. Get those four right and the panel works.
The Short Answer
The male hormone panel goes wrong more often through timing and technique than through choosing the wrong analytes. Testosterone peaks in the early morning and falls through the day by enough to move a result across a clinical threshold. Total testosterone without SHBG cannot be interpreted. Direct free testosterone immunoassays perform poorly. And LH and FSH, which locate the problem, are frequently omitted. Four fixes make the panel informative.
The Core Panel
Total testosterone, drawn before 10am. Diurnal variation is substantial, with morning values considerably higher, and the reference ranges were established on morning samples. Repeat any abnormal result on a separate morning, since within-person variation is large.
Sex hormone binding globulin. Required for interpretation. SHBG rises with age, hyperthyroidism, liver disease, oestrogens and some anticonvulsants, and falls with obesity, insulin resistance, hypothyroidism, glucocorticoids and androgen use. A normal total testosterone with high SHBG can mean low free testosterone, and the reverse also occurs.
Free testosterone, calculated. Calculated from total testosterone, SHBG and albumin, which performs considerably better than direct immunoassay. Equilibrium dialysis is the reference method and is rarely available. Direct free testosterone immunoassays are unreliable and should not be used where a calculation is possible.
Luteinising hormone and follicle-stimulating hormone. These locate the problem. High gonadotropins with low testosterone indicate a testicular cause, primary hypogonadism. Low or inappropriately normal gonadotropins with low testosterone indicate a pituitary or hypothalamic cause, secondary hypogonadism, which has a different investigation pathway including pituitary imaging in some cases.
Oestradiol, by a sensitive assay. Standard immunoassays perform poorly at male concentrations, so a result from a standard assay is unreliable.
Prolactin, where testosterone is low with low gonadotropins, to screen for a prolactinoma.
What Else Belongs Alongside
| Test | Why |
|---|---|
| Full blood count | Haematocrit; testosterone therapy raises it, and a raised baseline matters |
| HbA1c and fasting insulin | Insulin resistance lowers SHBG and testosterone; often the actual cause |
| Thyroid function | Both directions affect SHBG and symptoms |
| Ferritin and iron studies | Haemochromatosis causes secondary hypogonadism and is missed |
| Vitamin D | Associated with testosterone where status is low |
| Liver and kidney function | Affect SHBG and hormone metabolism |
| PSA, where relevant by age | Baseline before considering testosterone therapy |
| Sleep assessment | Sleep-disordered breathing is independently associated with low testosterone |
The haemochromatosis row deserves emphasis because it is a specific missed cause: iron overload damages the pituitary and produces secondary hypogonadism, and it is correctable. Raised ferritin with high transferrin saturation in a man with low testosterone should prompt genetic testing.
The insulin resistance row is the most common. Obesity and insulin resistance lower SHBG and total testosterone through several mechanisms including adipose aromatase activity, and in many men with low testosterone in midlife this is the cause rather than primary testicular failure.
The Interpretive Rules
Symptoms and levels must both be present. Low testosterone without symptoms and symptoms with normal testosterone are both common. Guideline positions require both to identify hypogonadism, and this is the most frequently ignored rule in this area.
Repeat before acting. A single low morning value should be confirmed on a separate morning. Biological variation, illness, poor sleep and acute stress all lower it transiently.
Do not measure during illness, sleep deprivation or a heavy training block with restricted intake, since the result will reflect the situation rather than a set point.
Reference ranges are population ranges. They vary between assays and laboratories, and a value near the lower limit in a symptomatic man warrants free testosterone calculation rather than dismissal.
Age-related decline is gradual, roughly one per cent per year, and in midlife health status contributes more than age in most men.
Look for the reversible cause first: obesity, sleep-disordered breathing, sleep restriction, energy deficit with high training volume, excess alcohol, opioids, glucocorticoids and anabolic steroid use with subsequent suppression. Several are common and all are addressable.
Testosterone Therapy, and What It Requires
Since this panel often leads there, the requirements are worth stating.
Therapy is appropriate for symptomatic, biochemically confirmed hypogonadism after reversible causes have been addressed, and it is a clinical decision with monitoring obligations.
What it does: improves libido, erectile function in some men, mood, lean mass and bone density, with effects on energy variable.
What it requires: baseline and monitored haematocrit, since erythrocytosis is the most common adverse effect; PSA monitoring by age and guideline; and awareness that it suppresses spermatogenesis and impairs fertility, which matters for anyone who may want children and is frequently under-discussed.
Cardiovascular safety has been debated for years, with a recent large randomised trial in men with hypogonadism and cardiovascular risk factors not showing an increase in major cardiovascular events, which is reassuring while not settling every question.
What it is not: an anti-ageing intervention for men with normal levels, where the evidence for benefit is limited and the suppression of endogenous production is a real cost.
What to avoid: self-directed therapy from unregulated sources, which carries dosing, quality and monitoring problems, and stopping abruptly after prolonged use, which leaves a suppressed axis.
Common Mistakes
Afternoon draw. Produces low values in men with normal morning testosterone. The single most common error.
No SHBG. Makes total testosterone uninterpretable in anyone with altered binding, which includes most men with obesity or insulin resistance.
Direct free testosterone assay. Unreliable; use a calculated value.
Standard oestradiol assay. Unreliable at male concentrations; request a sensitive assay.
No LH and FSH. Leaves the cause unlocated, which changes the pathway entirely.
Acting on one value. Biological variation is large.
Ignoring the reversible causes. Obesity, sleep-disordered breathing and opioid use are common, addressable and frequently skipped in favour of therapy.
Ordering a broad hormone panel with dozens of analytes. More measurements means more incidental abnormalities requiring explanation.
Getting the four core fixes right, morning draw, SHBG, calculated free testosterone and gonadotropins, converts a commonly misleading panel into a genuinely useful one.
The AEONNN Perspective
AEONNN's contribution to this panel is mostly technical, because that is where it fails. A morning draw before 10am, SHBG alongside total testosterone, calculated rather than directly assayed free testosterone, and a sensitive oestradiol assay are Quality layer requirements, and getting any of them wrong invalidates the panel regardless of breadth.
LH and FSH are the omission that matters most, since they locate the cause: high gonadotropins point to a testicular problem, low or inappropriately normal ones to a pituitary or hypothalamic one, and the two have different pathways.
The platform's routine response is to look for the reversible cause first, because in midlife it is usually present. Obesity and insulin resistance lower SHBG and total testosterone, sleep-disordered breathing is independently associated with low testosterone, and energy deficit with high training volume suppresses the axis. That makes Pillar 4 and Pillar 9 upstream of a Pillar 2 finding. The Consensus layer holds the rule most often ignored, which is that symptoms and levels must both be present, and the Safety layer holds the fertility suppression that testosterone therapy causes and that is frequently under-discussed.
Pillar Matrix mapping
Database Matrix layers
- Meta / Consensus Layer (JAMA, BMJ, specialty society positions)
- Quality / Formulation Layer (ConsumerLab, Labdoor)
- Evidence Layer (PubMed, Cochrane, ClinicalTrials.gov)
- Safety Layer (DrugBank, FAERS)
Frequently Asked
When should testosterone be measured?
Before 10am, since diurnal variation is substantial and reference ranges were established on morning samples. Any abnormal result should be repeated on a separate morning.
Why is SHBG needed?
It determines how much testosterone is free and active. A normal total testosterone with high SHBG can mean low free testosterone, and SHBG shifts with age, obesity, insulin resistance and thyroid status.
Should free testosterone be measured directly?
No, where a calculated value is possible. Direct immunoassays perform poorly. Calculation from total testosterone, SHBG and albumin is more reliable.
Why measure LH and FSH?
They locate the cause. High gonadotropins with low testosterone indicate a testicular cause; low or inappropriately normal ones indicate a pituitary or hypothalamic cause with a different pathway.
What reversible causes should be checked first?
Obesity and insulin resistance, sleep-disordered breathing, sleep restriction, energy deficit with high training volume, excess alcohol, opioids, glucocorticoids and prior anabolic steroid use.
Does testosterone therapy affect fertility?
Yes. It suppresses spermatogenesis and impairs fertility, which matters for anyone who may want children and is frequently under-discussed.
Is testosterone therapy an anti-aging intervention?
No. In men with normal levels the evidence for benefit is limited, and suppression of endogenous production is a real cost. It is appropriate for symptomatic, confirmed hypogonadism.
Evidence and review
Any dosage ranges cited here reflect the ranges used in published human trials, not personal recommendations. Evidence in this field moves, so this article is reviewed quarterly and carries its last-updated date above. Nothing here is intended as medical advice, and supplementation should be discussed with a qualified clinician, particularly alongside prescribed medication or an existing condition.