There is one hormone that falls so predictably with age that researchers use it to read your biological clock.

Yours has probably never been measured.

It is DHEA, along with its storage form DHEA-S, made mostly by your adrenal glands. It peaks in your twenties, then declines by roughly 1 to 2 per cent every year for the rest of your life. By the time a woman reaches menopause, her DHEA has dropped by around 60 per cent from its peak. By the eighth decade, only a tenth or so remains. Very few biomarkers decline this smoothly, which is exactly what makes this one worth understanding.

What lifts DHEA above a curiosity is what it does.

It is a precursor, the raw material your body converts into oestrogen and testosterone within the tissues. After menopause, when the ovaries step back, adrenal DHEA becomes one of the main sources of sex hormones a woman has left. In longevity research, people who carry higher DHEA-S for their age tend to show better cognitive function, lower cardiovascular risk and lower all-cause mortality. It is not a magic number. It is a useful one.

Here is the part I find most telling.

While DHEA falls year on year, cortisol, your main stress hormone, does not. It holds steady or even creeps up with age. The ratio between the two therefore shifts, slowly and predictably, towards more stress hormone and less of the restorative, building precursor. Chronic stress accelerates that shift. So when you feel as though your body has stopped repairing as quickly as it breaks down, that is not entirely in your head.

I am wary of the supplement hype around DHEA, because the evidence for simply taking it is genuinely mixed and it is not something to self-prescribe. What I am not wary of is measuring it. The DUTCH test maps DHEA-S alongside your full cortisol pattern and your sex hormones, which is the context that actually gives the number meaning. A figure on its own tells you very little. The same figure read next to your cortisol rhythm and your oestrogen tells a story.

Knowing where you sit on that curve is the difference between ageing by accident and ageing on your own terms.

The full picture is one test away. Understand your hormones → https://www.sannalife.health/dutch-test

Sources: 

• NIH Endotext, Adrenal Androgens and Aging;
• MDPI review on the cortisol-to-DHEA ratio in ageing (2025);
• clinical summaries on DHEA-S as a biological ageing marker.