Serum Cortisol

Hormones marker

Cortisol

Serum Cortisol

Category: Hormones
Unit: nmol/L

Primary stress hormone produced by the adrenal cortex. Regulates metabolism, immune response, and blood pressure. Levels follow a diurnal pattern (highest in the morning).

PED Notes

Elevated by intense training, caloric deficit, and psychological stress. Chronically elevated cortisol is catabolic and impairs recovery. Some AAS (especially Trenbolone) can increase cortisol-related symptoms. Timing of blood draw significantly affects results -- morning fasting samples are standard.

When high

Supplements (for chronically elevated cortisol):

  • Ashwagandha -- 300-600mg/day (5% withanolides, evening/post-workout, reduces cortisol 20-30%)
  • Rhodiola Rosea -- 200-400mg/day (morning, stress resilience)
  • Magnesium Glycinate -- 400mg before bed
  • Phosphatidylserine -- 400-600mg/day; well-evidenced acute cortisol blunting, especially when taken around training; most useful for exercise-induced cortisol spikes

Lifestyle:

  • Optimise sleep (7-9h)
  • Manage psychological stress

Pharmacological options (rarely used outside Cushing's syndrome):

  • Note that cortisol-lowering pharmacology is almost never appropriate for athletes; chronic mild elevation is best addressed with lifestyle, sleep, training load reduction, and adaptogens. The following agents are reserved for confirmed hypercortisolism (Cushing's) under endocrinology supervision only.
  • Metyrapone -- 11-beta-hydroxylase inhibitor; Cushing's syndrome only; causes androgen excess and hypertension; specialist-only
  • Ketoconazole -- adrenal steroidogenesis inhibitor; hepatotoxic, requires LFT monitoring; specialist-only
  • Mifepristone -- glucocorticoid receptor antagonist; approved for Cushing's with diabetes; not used for lifestyle-driven elevation
  • For psychological stress driving chronic elevation, address the upstream driver (SSRI, CBT, beta-blockers for situational anxiety) rather than the cortisol itself; avoid tianeptine due to abuse potential

History Chart

Reading History

Frequently Asked Questions

Reference Ranges

Standard Range

110 - 550 nmol/L

Statistics