Andropause
The gradual decline of testosterone — and other hormones — in middle-aged and older men. Unlike female perimenopause, it is slow, quiet, and almost universally attributed to stress, ageing, or poor lifestyle rather than investigated as a hormonal condition.
Late-onset hypogonadism (clinically defined as low testosterone with symptoms) affects an estimated 10–40% of men over 45. Symptoms are real, they compound, and many are highly treatable.
What is actually happening
Testosterone peaks at around 19–20. From the late 20s, free testosterone begins a decline of ~1–2% per year. By the mid-50s, many men have free testosterone 30–50% lower than their peak. Total testosterone often looks normal because SHBG (a binding protein) rises with age, hiding the true decline.
Free testosterone is what matters.SHBG binds testosterone and renders it biologically inactive. A man with “normal” total testosterone but high SHBG may have very low free testosterone — and all the symptoms that come with it.
Visceral fat accelerates the decline. Fat tissue contains the enzyme aromatase, which converts testosterone to estrogen. As men age and fat accumulates, aromatase activity rises, estrogen rises, and testosterone falls further. This creates a self-reinforcing cycle.
Sleep is a major driver. Testosterone is released in pulses during sleep — especially REM sleep. Sleep disruption directly reduces testosterone. Sleep apnoea, common in middle-aged men, is one of the most frequently missed and reversible causes of low testosterone.
The stress axis compounds it. Cortisol directly inhibits Leydig cell testosterone production. Chronic stress → chronically elevated cortisol → lower testosterone. Treating stress and sleep is not optional — it is mechanistically necessary.
- → Decline is so gradual that men adapt without realising they have lost function.
- → Symptoms (fatigue, low mood, reduced drive) are attributed to work stress or getting older.
- → Men are less likely to report symptoms or seek evaluation for them.
- → Testosterone is rarely tested unless a man specifically requests it.
- → “Normal” total testosterone can mask low free testosterone — most labs only test total.
Visceral fat → aromatase converts T to estrogen → testosterone falls → muscle loss → more fat accumulation → more aromatase. Chronic stress → cortisol → directly suppresses testosterone production. Sleep apnoea → disrupted REM → testosterone release suppressed.
Each driver compounds the others. Treatment requires addressing all three.
Primary: testes fail to produce testosterone despite normal LH/FSH (high LH + low T = testicular problem).
Secondary: pituitary or hypothalamus fails to signal the testes (low LH + low T = central problem — often reversible with clomiphene).
LH + FSH testing is essential to identify which — because treatment differs.
Symptoms of andropause
These symptoms are real, have specific hormonal causes, and are not simply “normal ageing.”
A persistent flat, switched-off feeling — not explained by lack of sleep or overwork. Testosterone drives mitochondrial energy production, dopaminergic motivation, and red blood cell count. As it falls, energy follows. This is one of the most common and most dismissed symptoms of low testosterone in men.
Testosterone is the primary driver of male libido — desire, initiation, and sexual interest. Falling testosterone directly reduces libido. Estradiol (converted from testosterone) also plays a role in sexual function and pleasure. Prolactin elevation (from a pituitary adenoma) can suppress both testosterone and libido.
Testosterone has direct effects on mood, motivation, and sense of wellbeing via dopaminergic and serotonergic pathways. Epidemiological studies find men with low testosterone have a significantly higher prevalence of depression (some studies report 2–4× higher) — though the relationship is bidirectional: depression itself suppresses testosterone. The presentation often differs from typical depression — it presents as irritability, emotional numbness, withdrawal, anhedonia, or loss of competitive drive rather than sadness.
Testosterone directly stimulates muscle protein synthesis and inhibits fat storage. As testosterone falls and visceral fat accumulates, the situation compounds: fat tissue contains the enzyme aromatase, which converts testosterone to estrogen. More fat → more aromatase → more estrogen and less testosterone → more fat. Breaking this cycle is central to male hormonal health.
Testosterone is released primarily during sleep — especially during REM sleep. Poor sleep quality directly reduces testosterone. Conversely, low testosterone increases the risk of sleep apnoea (via effects on upper airway tone and respiratory drive). Sleep apnoea then further suppresses testosterone — creating a self-reinforcing cycle.
Testosterone and its conversion to estradiol in the brain support spatial memory, processing speed, working memory, and verbal fluency. Men with low testosterone perform worse on cognitive tests. Cognitive symptoms are often written off as 'stress' or 'ageing' rather than investigated hormonally.
Men lose bone density with age — but this is significantly underrecognised and underscreened. Both testosterone and estradiol are essential for bone maintenance in men. Testosterone stimulates osteoblasts (bone builders). Estradiol (converted from testosterone) suppresses osteoclasts (bone reapers). When both fall, bone loss accelerates.
Low testosterone is an independent risk factor for cardiovascular disease in men. Testosterone maintains arterial flexibility, supports healthy lipid profiles (raises HDL, lowers LDL), reduces visceral fat, and improves insulin sensitivity. When testosterone falls, all of these protective effects diminish. Men with the lowest testosterone have the highest cardiovascular mortality.
What actually helps
Evidence-rated interventions — hormonal, lifestyle, and supplements.
Restores testosterone to mid-normal range. Available as daily gels, injections (weekly to every 10–14 weeks), patches, or pellets. Indicated for confirmed hypogonadism (low testosterone + symptoms).
Stimulates the pituitary to produce more LH and FSH, which in turn raises endogenous testosterone. Preserves fertility. Used off-label for secondary hypogonadism (where the problem is in the HPG axis, not the testes).
The single most effective non-pharmacological intervention for testosterone levels. Compound movements (squats, deadlifts, bench press) produce the strongest acute testosterone and GH response. Consistent training over months raises baseline testosterone and GH.
Testosterone is released during sleep, especially REM sleep. Even one week of sleep restriction to 5 hours per night reduces testosterone by 10–15% in young men. Sleep apnoea treatment alone can raise testosterone substantially.
Visceral fat is the primary source of aromatase in men — the enzyme that converts testosterone to estrogen. A 10% reduction in body weight in obese men raises testosterone by ~25%. Diet quality (adequate protein, lower processed carbohydrates) and caloric deficit are the primary tools.
Zinc is essential for testosterone synthesis and LH receptor function. Deficiency — common in men with poor diets, high alcohol intake, or GI conditions — directly reduces testosterone. Supplementation raises testosterone in deficient men.
Vitamin D receptors are present in Leydig cells (testosterone-producing cells in the testes). Deficiency is associated with lower testosterone. Studies show supplementation raises testosterone modestly in deficient men.
An adaptogen that reduces cortisol and has been shown in multiple RCTs to raise testosterone modestly (8–15%) and improve strength, recovery, and sexual function. Mechanism: cortisol suppresses testosterone production; lowering cortisol via HPA modulation allows testosterone to rise.
Lab guide — what to test and why
The most important rule: always test total testosterone in the morning (before 10am) — levels peak on waking and fall by 30–40% through the day. A single afternoon test is unreliable.
How andropause compares to perimenopause
- → Gradual — 1–2% per year from late 20s
- → Often unnoticed for a decade
- → No clear end-point (not like last period)
- → Highly modifiable by lifestyle
- → Undertested, undertreated
- → Rapid and erratic — volatile before declining
- → Often dramatically symptomatic
- → Clear staging (STRAW+10) and endpoint
- → Multiple axes destabilise simultaneously
- → Average 3+ year delay to diagnosis
Both are real. Both are treatable. Neither is something to simply endure as “part of ageing.”