How does the Curve measure cortisol?

A small sensor sits on the underside of the band. A thin layer is shaped to lock onto cortisol; when cortisol in sweat attaches to it, the sensor converts that into a small electrical signal, and a second electrode alongside it corrects for background noise.

Is the Curve a medical device?

No. It is a general wellness device under Health Canada and FDA guidance. It does not diagnose, treat, or cure any condition. Medical-device clearance is a claim that has to be bought with clinical evidence, and that evidence does not exist yet.

The Science: How the Curve Reads Cortisol From Sweat

Q: Is sweat cortisol the same as blood cortisol?

Sweat carries the free fraction of cortisol, the portion not bound to carrier proteins and the portion that is biologically active. Blood tests usually report total cortisol, most of which is protein-bound. They are related but not identical measurements.

Q: How accurate is the Auromone Curve?

There is no published accuracy figure. The device is in development and has not been validated against a laboratory reference. When that work is complete we will publish the figure together with the method behind it.

From sweat to a curve.

Four steps, and the interesting one is the first. Sweat carries the free fraction of cortisol: the portion not bound to carrier proteins, and the portion your tissues actually respond to.

Step one

The free fraction

Most circulating cortisol is protein-bound and unavailable to tissue. Sweat carries the unbound part.

Step two

It binds

A thin layer on the sensor surface is shaped so cortisol molecules lock into it.

Step three

It becomes a signal

That binding is converted into a small electrical signal. A second electrode alongside corrects for background noise, which on a wrist across a day is substantial.

Step four

It becomes a shape

Read continuously rather than at intervals, so the sharp rise after waking and the overnight floor are both in view.

Where the evidence actually stands.

Stated as a pair, because a claim with a footnote is not the same thing as an honest account of what is and is not established.

Established

Sweat carries the biologically active fraction.

This is settled endocrinology, not a company claim. The unbound portion is the one that acts on tissue, and it is the portion sweat carries. It is the reason this approach is interesting rather than merely convenient.

Not yet earned

No accuracy figure, because none has been earned.

The Curve has not been validated against a laboratory reference. We removed an earlier figure from this site rather than let it stand on work that did not support it. When validation runs, the number and its method will be published together.

Established

Reading continuously changes what is visible.

The features that matter most in a cortisol day are the ones a clinic-hour sample misses: the sharp post-waking rise and the overnight floor. That is a property of the sampling, not a claim about this device.

Not yet earned

A general wellness device, not a medical one.

Medical-device clearance is a claim bought with clinical evidence. We would like to earn it. We have not, and no third-party validation exists.

Why the free fraction is the one that matters.

A standard serum test typically reports total cortisol, the bound and unbound together. Most of that total is attached to carrier proteins and is not available to act on tissue.

So comparing a sweat reading directly against a total-serum number is not a like-for-like comparison, and any validation work has to account for that rather than assume the two should match. That is a harder study to design, and it is the honest one.

The physiology this rests on is covered in Cortisol 101; the practical comparison between methods is in measuring cortisol.

Free vs total

Common questions

How accurate is the Curve?

There is no published figure. The device has not been validated against a laboratory reference. When that work is done, the number and the method behind it will be published together. Until then, treat the absence of a figure as the honest answer rather than an oversight.

Is sweat cortisol the same as blood cortisol?

Not identical. Sweat carries the free, biologically active fraction; a standard blood test usually reports total cortisol, most of which is bound to carrier proteins. They are related quantities measuring different things, and validation has to account for that rather than assume they should agree exactly.

Is this a medical device?

No. It is a general wellness device under Health Canada and FDA guidance, and it does not diagnose, treat, or cure anything. Earning medical-device clearance is a longer-term ambition that requires clinical evidence we do not have.

Will you publish your methodology?

Yes. That is the intent of this page. Some detail is held back for now while intellectual property filings are in progress, and we would rather say that plainly than pretend the gaps are not there.

Auromone Curve is a general wellness device under Health Canada and FDA guidance. It is not intended to diagnose, treat, or cure any condition. The product is in development and final performance may differ from the specifications described here.

How the measurement works, including what it cannot do yet.