Cortisol in men and women: what differs, and why it matters for testing

On average, men have somewhat higher cortisol than women before the menopause, both in the daily rhythm and in the long-term levels measured in hair. The difference is modest, the ranges overlap a great deal, and after the menopause it disappears. For anyone having a cortisol test, a bigger issue is oestrogen. The combined pill, some forms of HRT and pregnancy raise the protein that carries cortisol in the blood, which can make a blood test read high even when the body's active cortisol is normal. Hair is far less affected. This guide covers what differs between men and women and what it means for each kind of test.

Do men and women have different cortisol levels?

A 2024 review in Endocrine Reviews describes men as having higher cortisol output than premenopausal women, with a higher daily peak, a higher overnight low and a larger rise after waking. After the menopause there is no longer a difference.¹ Not every study agrees on the morning rise, though. In three earlier studies of 152 people, free cortisol rose by 50 to 75 per cent within 30 minutes of waking, and premenopausal women had a stronger rise and a later peak than men.² Our guide to the cortisol daily rhythm explains these measures.

The differences show most clearly under stress. In a study of 81 healthy adults given a standard public-speaking stress test, men had a larger response in ACTH, the pituitary hormone that drives cortisol, than any group of women. Free cortisol in saliva was another matter: women in the second half of the menstrual cycle (the luteal phase) responded as strongly as men, and both responded more than women in the first half of the cycle or on the pill. Total cortisol in the blood showed no difference between men and women at all.³ So whether men or women look "higher" depends partly on what is measured, when and how.

Hair cortisol in men and women

Hair gives a steadier picture, because one sample averages several months and several menstrual cycles. Most studies find somewhat higher hair cortisol in men:

• In 360 people aged 1 to 91, men had higher hair cortisol than women.⁴
• In 283 older adults in Rotterdam, the averages were 26.3 pg/mg in men and 21.0 pg/mg in women.⁵
• In 3,507 people aged 59 to 83 in the Whitehall II study, women's hair cortisol was 17.0 per cent lower than men's.⁶

The pattern is not universal. In two other cohorts, 654 German adults and 760 Dutch adults, men had higher levels in simple comparisons, but sex was no longer a significant factor once age and other factors such as smoking, washing frequency and season were taken into account.⁷⁸ A 2026 study that set a reference range in 256 healthy adults by mass spectrometry found no difference between men and women.⁹ Researchers treat sex as one of several factors to allow for when comparing groups, alongside age, hair washing, hair treatments and contraceptive use.¹⁰ For an individual, the practical point is simple: compare your result with your laboratory's range and with your own earlier results.

The pill, HRT and blood tests

About 90 per cent of the cortisol in blood is bound to a carrier protein, corticosteroid-binding globulin (CBG). Standard blood tests measure total cortisol, bound and free together. Oestrogen taken by mouth, and the high oestrogen of pregnancy, raise CBG, which gives a falsely high total cortisol. Saliva and urine tests measure free cortisol and are not affected by changes in CBG.¹

The effect is large. In a study of 37 women, those taking oral oestrogen had 67 per cent higher total blood cortisol than women not taking it (660.9 against 395.4 nmol/L), and CBG was more than twice as high. Women using oestrogen through the skin had no rise in total cortisol, and salivary cortisol was similar in all three groups.¹¹ This is why clinical guidance builds in precautions:

• NICE advises stopping oral oestrogen for six weeks before a blood cortisol test for suspected adrenal insufficiency, because otherwise cortisol will read falsely high.¹²
• The overnight dexamethasone suppression test, used to check for Cushing's syndrome, gives false positives in 50 per cent of women on the combined pill, so the Endocrine Society advises stopping oestrogen-containing drugs for six weeks beforehand where possible.¹³
• Women on the combined pill need separate reference limits for the Synacthen test, according to a study of 165 healthy volunteers.¹⁴

The pill can also change free cortisol responses. In the stress study above, women on the pill had markedly lower free cortisol responses, and the authors recommended measuring both free and total cortisol.³ See the blood cortisol test guide for how to prepare.

Why hair is far less affected by the pill

Hair studies of hormonal contraception point in different directions and show small effects at most. A 2026 study found no difference in hair cortisol between combined pill users and non-users (median 2.22 against 2.59 pg/mg).¹⁵ A South London study linked hormonal contraceptives to somewhat higher hair cortisol,¹⁶ a study of 360 people found no effect,⁴ and in the Dutch study of 760 adults contraceptive use was linked to hair cortisol in simple analyses but not once other factors were allowed for.⁸ None of that compares with the two-thirds rise in total blood cortisol.

One likely reason is that hair appears to reflect free cortisol. Researchers who compared hair with a month of repeated saliva samples concluded that hair reliably estimates long-term free cortisol production,¹⁷ and free cortisol in saliva was unchanged by oral oestrogen.¹¹ For a woman on the pill or oral HRT who wants to know her long-term cortisol, that makes hair the more straightforward measure. The hair vs blood comparison goes into this further.

Pregnancy, the menopause and later life

Pregnancy raises cortisol in two ways. High oestrogen raises CBG, so total blood cortisol reads high,¹ and long-term cortisol genuinely rises too: hair from the third trimester held twice as much cortisol as hair from women who were not pregnant.¹⁸ See cortisol, fertility and pregnancy.

After the menopause, the difference in cortisol output between men and women disappears.¹ Research on hair cortisol around the menopause is limited to small studies. In 145 women aged 50 to 64, higher hair cortisol was linked to worse sleep quality,¹⁹ and in a pilot study of 45 midlife Latina women, hot flushes and night sweats were linked to higher hair cortisol, although the link weakened after allowing for perceived stress.²⁰ Neither study shows that hair cortisol can track or diagnose the menopause. See cortisol and the menopause and cortisol and ageing.

Ranges and conditions that differ by sex

Some reference ranges are set separately for men and women. The US MedlinePlus encyclopedia gives example normal values for 24-hour urine cortisol of below 45 µg (124 nmol) a day for women and below 60 µg (165 nmol) for men.²¹ For the Synacthen test, one immunoassay's lower limit at 30 minutes was 524 nmol/L in women and 574 nmol/L in men.¹⁴ Always read a result against the range on your own report.

The cortisol conditions themselves are more common in women. Cushing's syndrome is much more common in women than in men,²² and more women than men have Addison's disease, which most often starts between the ages of 30 and 50.²³

What this means if you are having a test

For a blood test, tell the doctor or laboratory if you take the combined pill or oral HRT, use oestrogen patches or gel, or are pregnant, because it changes how the result should be read. For saliva, mention where you are in your cycle if the test is about stress responses. For hair, tell the laboratory about hormonal contraception and hair treatments, and judge your result against your own earlier results from the same laboratory. Whatever the test, it does not diagnose a condition on its own; symptoms that could mean an adrenal problem need a doctor's assessment.