What happens to men after 40. The complete hormonal arc.

Testosterone declines approximately 1% per year after age 30. GH pulse amplitude drops 14% per decade. DHEA falls continuously from the mid-20s. The hormonal arc of male aging is not a cliff. It is a slope. And the slope is manageable.

I. The hormonal decline timeline.

Testosterone peaks at approximately age 20 to 25. Decline begins in the late 20s and accelerates after 40. Total testosterone falls approximately 1 to 2% per year. Free testosterone declines faster still, driven by rising sex hormone-binding globulin (SHBG) with age: SHBG binds testosterone and removes it from bioavailable circulation, compounding the total decline at the free fraction level. verified [I]

The Baltimore Longitudinal Study of Aging quantified this trajectory precisely. Harman et al. reported a decline of approximately 110 ng/dL per decade in healthy men, a finding that held across the full cohort with no discrete threshold or inflection point. The decline is linear. It begins before most men expect it and continues without natural arrest. verified [I]

Growth hormone. Pulsatile GH secretion declines approximately 14% per decade after age 20. IGF-1 falls in parallel. This is the somatopause: a sustained reduction in anabolic signaling that affects muscle mass, fat distribution, sleep architecture, and recovery capacity. Unlike the gonadal axis, the somatopause does not produce a clear clinical threshold in most laboratory reference ranges, which makes it systematically underdiagnosed. verified [V]

DHEA and DHEA-S. DHEA peaks in the mid-20s and declines continuously without any compensatory mechanism. By age 70, DHEA-S is approximately 20% of peak values. This is adrenopause: a slow withdrawal of the adrenal androgen precursor that contributes to testosterone and estradiol pools, supports immune function, and influences mood and energy. verified [III]

Melatonin. Pineal calcification and reduced melatonin synthesis begin after age 40. By age 60, nocturnal melatonin output is substantially reduced relative to young-adult levels. Consequences extend beyond sleep: melatonin is a potent antioxidant and plays a role in circadian entrainment of the hormonal axes listed above. Its decline does not occur in isolation.

II. Symptoms and their hormonal correlates.

Low energy and fatigue correlate with testosterone, IGF-1, thyroid function, cortisol pattern, and mitochondrial efficiency. Fatigue is not a diagnostic criterion for hypogonadism alone. A man presenting with fatigue needs a full panel, not a testosterone prescription.

Body composition shift (increasing visceral fat, decreasing lean mass) is driven primarily by testosterone decline and GH/IGF-1 decline acting together, compounded by emerging insulin resistance. Visceral fat itself is an endocrine organ: it aromatizes testosterone to estradiol and amplifies the hormonal disruption. The composition shift is both a symptom of hormonal decline and a cause of further hormonal disruption.

Cognitive changes (brain fog, reduced working memory, diminished processing speed) correlate with testosterone, estradiol (which declines in some older men as testosterone substrate falls), IGF-1, and BDNF. The cognitive dimension of andropause is underappreciated in clinical practice.

Reduced libido is multi-factorial. Testosterone, estradiol, dopamine tone, the melanocortin-4 receptor (MC4R) pathway, and relationship context all contribute. Optimizing testosterone alone restores libido in a subset of men. A significant fraction requires a broader hormonal and neurochemical assessment before improvement is achieved.

Sleep deterioration involves multiple mechanisms: reduced slow-wave sleep (SWS) as GH pulse amplitude declines (GH is primarily secreted during SWS), reduced melatonin, and rising prevalence of obstructive sleep apnea with increasing visceral adiposity. Sleep disruption accelerates every other hormonal decline listed above. It is both symptom and cause.

III. When TRT is indicated.

The Endocrine Society guideline is the most widely cited threshold: testosterone replacement therapy is indicated for men with total testosterone consistently below 300 ng/dL accompanied by symptoms attributable to deficiency. TRT is not indicated for age-related decline alone, in the absence of symptoms. verified [II]

The optimization lens applies a different standard. Many clinicians in optimization medicine treat total testosterone below 400 to 500 ng/dL as a functional deficiency in symptomatic men, targeting a range of 600 to 900 ng/dL. This approach sits outside the Endocrine Society guideline but reflects widespread clinical practice. It is not reckless; it is a deliberate decision to define sufficiency differently from the deficiency threshold.

IV. The somatopause intervention.

GH secretagogue protocols address the somatopause directly. CJC-1295 combined with ipamorelin at bedtime is the standard starting protocol for men over 40 with documented low IGF-1 or functional GH decline symptoms. The combination leverages a GHRH analog (CJC-1295) plus a ghrelin mimetic (ipamorelin) to restore pulsatile GH secretion within physiological amplitude. clinical practice consensus

Target IGF-1 on GH secretagogues: upper quartile of the age-adjusted reference range. For a 50-year-old man, this is approximately 150 to 220 ng/mL. Monitor IGF-1 at 3 months, then every 6 months. If IGF-1 exceeds 300 ng/mL, reduce dose. Chronically supraphysiological IGF-1 is not the objective. The objective is restoration to a healthy functional range, not maximum output.

Tesamorelin is an FDA-approved GHRH analog with a demonstrated effect on visceral fat reduction in HIV-associated lipodystrophy. Off-label use for age-related GH decline is well-established in optimization medicine. Tesamorelin is more potent than CJC-1295 and carries a higher cost. Falutz et al. demonstrated significant reductions in visceral adipose tissue in a controlled trial published in the New England Journal of Medicine. verified [IV]

V. DHEA and adrenopause.

DHEA replacement is indicated for men with DHEA-S below 150 mcg/dL and symptoms including fatigue, low libido, mood instability, or impaired body composition. Standard oral dosing is 25 to 50 mg per day. The DHEAge study by Baulieu et al. demonstrated improvements in bone density, skin condition, libido, and subjective wellbeing in older adults supplemented with DHEA for one year. verified [III]

DHEA is a precursor. It converts peripherally to both testosterone and estradiol. After initiating DHEA, monitor testosterone and estradiol at 6 to 8 weeks. The conversion ratio varies by individual. Some men experience an estradiol increase that warrants attention; others convert primarily to testosterone and see the intended anabolic and androgenic benefit.

7-keto DHEA is a distinct compound. It is a non-androgenic DHEA metabolite that does not convert to sex hormones. Its primary clinical application is thermogenesis and weight management. It does not substitute for DHEA in the adrenopause context. These are different compounds with different indications, and conflating them is a common error.

VI. The complete andropause protocol sequence.

Step 1. Full hormonal baseline across all four axes. Total testosterone, free testosterone, SHBG, estradiol, LH, FSH, DHEA-S, IGF-1, fasting insulin, thyroid panel (TSH, free T3, free T4), and cortisol (AM, ideally 4-point salivary). Sleep study if OSA is suspected. No optimization begins before the baseline is complete.

Step 2. Address the metabolic foundation. Insulin resistance, thyroid dysfunction, disordered sleep, and chronic cortisol dysregulation all suppress the hormonal axes being treated. Optimizing testosterone in a man with uncontrolled insulin resistance and untreated sleep apnea produces attenuated and unstable results. The foundation precedes the optimization.

Step 3. Testosterone optimization if indicated. Dose to upper-normal physiological range, not supraphysiological. Monitor hematocrit, estradiol, PSA, and blood pressure at 6 to 8 weeks after initiation and every 6 months thereafter.

Step 4. GH secretagogue protocol if IGF-1 is low-normal or somatopause symptoms are present. CJC-1295 plus ipamorelin at bedtime. Monitor IGF-1 at 3 months.

Step 5. DHEA if DHEA-S is below 150 mcg/dL. 25 to 50 mg oral daily. Monitor testosterone and estradiol at 6 to 8 weeks.

Step 6. Longevity tier compounds (NAD+, MOTS-c, SS-31, Epithalon) once the hormonal foundation is stable. These compounds amplify a functioning system. Deployed on a dysfunctional hormonal substrate, their benefit is attenuated.

THE PIVOTAL PROTOCOL is an intelligence and education layer, not a prescriber. The mechanisms and clinical frameworks described here are derived from the cited literature and from Pivotal's own protocol design history. Every clinical decision belongs to a licensed physician with full knowledge of the individual case. Begin a conversation. Do not begin self-administration from a website.