Essential Hormone Tests for Longevity Optimization
Which hormones are worth measuring, when to draw them, and why timing and free versus total distinctions matter more than adding more analytes.
The Short Answer
Hormone testing goes wrong more often through timing and interpretation than through choosing the wrong analyte. Testosterone varies across the day by enough to change a clinical conclusion. Female reproductive hormones are meaningless without knowing the cycle day. Thyroid results shift with acute illness. And free hormone matters more than total in several cases while being harder to measure reliably. Getting those four things right does more than adding analytes to a panel.
The Core Panel for Men
Total testosterone, drawn in the morning. Levels peak in the early morning and fall through the day, with a difference large enough that an afternoon draw can produce a low result in a man with normal morning levels. Draw before 10am, fasting is not required but is conventional, and repeat any abnormal result on a separate morning before acting on it.
Sex hormone binding globulin. Required to interpret total testosterone. SHBG rises with age, with thyroid excess and with liver disease, and falls with obesity, insulin resistance and hypothyroidism. A normal total testosterone with high SHBG can mean low free testosterone.
Free testosterone, calculated rather than directly assayed where possible. Calculated free testosterone from total testosterone, SHBG and albumin is generally more reliable than direct immunoassay measurement, which performs poorly. Equilibrium dialysis is the reference method and is rarely available.
Luteinising hormone and follicle-stimulating hormone. These distinguish a testicular cause, where they are high, from a pituitary or hypothalamic cause, where they are low or normal alongside low testosterone. This distinction changes the clinical pathway entirely and is often omitted.
Oestradiol, measured by a sensitive assay, since standard assays perform poorly at male concentrations.
Prolactin, where testosterone is low with low gonadotropins, to screen for a pituitary cause.
The Core Panel for Women
Timing is the dominant issue here, and cycle day is not optional information.
In a menstruating woman: follicle-stimulating hormone, luteinising hormone and oestradiol on days 2 to 5 of the cycle for a baseline. Progesterone around day 21, or roughly seven days before the expected period, to assess ovulation. Results without a cycle day attached are not interpretable.
Total and free testosterone with SHBG, where there are features of androgen excess. Also DHEA-S in that context.
Anti-Müllerian hormone, which reflects ovarian reserve and is relatively cycle-independent. Useful for fertility questions and not a general longevity marker.
Prolactin, where cycles are irregular or absent.
In perimenopause: FSH and oestradiol fluctuate substantially, so a single result cannot confirm or exclude the transition. Perimenopause is identified clinically on symptoms and cycle pattern, and testing is mainly to exclude other causes. This is worth knowing before paying for a panel that cannot answer the question.
Post-menopause: routine hormone monitoring is not generally indicated unless on replacement therapy or investigating a specific problem.
Thyroid, Done Properly
| Test | Role |
|---|---|
| TSH | First-line screen; sensitive to primary thyroid dysfunction |
| Free T4 | Confirms and grades; needed where TSH is abnormal or a pituitary cause is possible |
| Free T3 | Useful in specific contexts; poor correlation with symptoms in most people |
| Thyroid peroxidase antibodies | Identifies autoimmune thyroiditis, which changes prognosis and monitoring |
| Reverse T3 | Rises in illness, fasting and energy deficit; not validated as a target for intervention |
Two cautions. Thyroid results shift with acute illness, in a pattern sometimes called non-thyroidal illness syndrome, so testing during or shortly after illness can produce a misleading picture. And reverse T3 is heavily marketed in wellness contexts as an explanation for symptoms despite not being a validated target for intervention. It rises appropriately in energy deficit, which means it is often reporting the restriction rather than a thyroid problem.
Iodine and selenium status are relevant to thyroid function, and excessive iodine supplementation can precipitate dysfunction in susceptible people, which is a reason against high-dose iodine without a demonstrated need.
What Not to Bother With
Salivary cortisol panels for adrenal fatigue. Adrenal fatigue is not a recognised condition, and these panels are not validated for it. Genuine adrenal insufficiency requires specific clinical testing and is rare.
Direct free testosterone immunoassay, where a calculated value is available. The direct assay performs poorly and produces misleading results.
Random single measurements of anything pulsatile. Growth hormone is secreted in pulses and a random level tells you almost nothing; IGF-1 is the appropriate proxy where growth hormone status is a question.
Oestradiol in men by standard assay. Standard assays perform poorly at male concentrations, so the result is unreliable unless a sensitive assay was used.
Broad hormone panels with dozens of analytes, where the number of measurements guarantees some fall outside reference ranges by chance, generating findings that require explanation and often supplementation.
Testing during acute illness, extreme training load or active dieting, which measures the situation rather than a set point.
How to Interpret What Comes Back
Reference ranges are population ranges, not optimal ranges. They typically describe the middle 95 per cent of a reference population, which in some cases includes people with unrecognised problems. A result inside the range is not automatically fine, and a result marginally outside it is not automatically a problem.
Symptoms and levels must both be present. Low testosterone without symptoms and symptoms with normal testosterone are both common, and neither is a straightforward case for intervention. This is the single most common interpretive error in this Pillar.
Repeat before acting. Single abnormal results, particularly testosterone, should be confirmed on a separate morning draw. Biological and analytical variation are both substantial.
Trends matter more than single values, which requires the same laboratory and the same assay, since methods differ enough that cross-laboratory comparison introduces artefacts.
Look for the confounder before the hormonal explanation. Sleep, energy availability, adiposity, training load, alcohol, acute illness and medications all shift these results, and correcting the confounder is often the intervention.
A Sensible Testing Schedule
Baseline, once, if there are symptoms or you want a reference: the core panel for your sex, plus thyroid function, alongside a standard metabolic panel, vitamin D and ferritin, since these explain many symptoms attributed to hormones.
Repeat any abnormal result on a separate occasion before acting.
Every one to two years if asymptomatic and building a record, or annually from midlife if you are tracking a trend.
Three months after any intervention, whether that is a lifestyle change, a corrected shortfall or a clinical intervention, since most hormonal responses take that long to stabilise.
Immediately, clinically, for: loss of morning erections with low libido and fatigue in men, absent or newly irregular periods, galactorrhoea, visual field changes or headaches suggesting a pituitary cause, or symptoms of thyroid excess or deficit.
Testing is worth doing and it is not worth doing repeatedly at short intervals. The most common failure in this Pillar is a large panel drawn at the wrong time, interpreted against population ranges, and acted on without repeating.
The AEONNN Perspective
AEONNN's contribution in Pillar 2 is mostly about timing and interpretation rather than about which analytes to add. Morning draws for testosterone, cycle day for female reproductive hormones, calculated rather than directly assayed free testosterone, sensitive assays for male oestradiol: the Quality layer holds these as assay-level requirements, and getting them wrong invalidates the panel regardless of how comprehensive it is.
The platform will not act on a single abnormal result, and it will not act on a level without symptoms. Both positions come from the Consensus layer, where clinical guidance is considerably more conservative than wellness testing practice.
Two exclusions are explicit. Salivary cortisol panels for adrenal fatigue are not validated and are not read. Reverse T3 rises appropriately in energy deficit and illness and is not a validated target, so a stack change on its basis would be intervening on an adaptation. The platform's routine response to a hormonal complaint is to check the confounders first, sleep, energy availability, adiposity, training load, alcohol and medications, because correcting one of those is often the intervention.
Pillar Matrix mapping
Database Matrix layers
- Evidence Layer (PubMed, Cochrane, ClinicalTrials.gov)
- Meta / Consensus Layer (JAMA, BMJ, specialty society positions)
- Quality / Formulation Layer (ConsumerLab, Labdoor)
- Safety Layer (DrugBank, FAERS)
Frequently Asked
When should testosterone be measured?
In the morning, before 10am, since levels peak early and fall through the day by enough to change a clinical conclusion. Any abnormal result should be repeated on a separate morning.
Why does SHBG matter?
Sex hormone binding globulin 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, thyroid status and insulin resistance.
Should free testosterone be measured directly?
Preferably not. Direct immunoassay performs poorly. Calculated free testosterone from total testosterone, SHBG and albumin is more reliable, and equilibrium dialysis is the reference method.
When in the cycle should female hormones be tested?
FSH, LH and oestradiol on days 2 to 5 for a baseline, and progesterone around day 21 to assess ovulation. Results without a cycle day attached are not interpretable.
Can a blood test confirm perimenopause?
No. FSH and oestradiol fluctuate substantially through the transition, so a single result cannot confirm or exclude it. Perimenopause is identified clinically on symptoms and cycle pattern.
Is reverse T3 worth measuring?
It is not a validated target for intervention. It rises appropriately in illness, fasting and energy deficit, which means it often reports the restriction rather than a thyroid problem.
Why not order a large hormone panel?
The more analytes measured, the more will fall outside reference ranges by chance, generating findings that require explanation. Timing and interpretation matter more than breadth.
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.