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The refill

Cortisol sensors.

180 founders have a plan reserved · founder pricing locked

The swappable strip that does the reading. Each sensor measures cortisol from your sweat for 14 days, then you snap in a fresh one. It's the only part of the Curve that wears out.

CA$24CA$29Save 17%

Per 4-pack · about 8 weeks of continuous wear · auto-ships before you run out.

Prices shown are target prices and may differ from the final sale price.

Reserve sensors
  • 14 days each, a 4-pack covers about two months.
  • Fits every Curve band, and every future hormone module.
  • Subscribers get priority access to new hormone sensors first.
Free shipping
Ships before you run out
Cancel any time
Recyclable sensors
A ten-second ritual

Swap it like a watch strap.

No tools, no clinic, no waiting. When a sensor reaches day 14, the app tells you, and the change takes seconds.

1 · Pop out the old

The magnetic tray releases the spent sensor with a press. Drop it in the recycling sleeve it came in.

2 · Snap in the fresh

A new sensor clicks into place by magnet. It seats the same way every time, so contact is always right.

3 · Keep reading

The app picks the new sensor up automatically and your curve continues without a gap.

17%

off every 4-pack on subscribe & save, and it ships before you run out.

The only part of Curve that wears out costs less than a coffee a week to replace.
Auromone — on the cost of staying continuous
Cancel any timeShips before you run outFits every Curve bandRecyclable
What's actually happening

It catches the molecule, not a proxy.

Each sensor carries an aptamer layer imprinted to the cortisol molecule. When cortisol binds, it shifts a tiny electrical signal that a matched control electrode cleans of drift, down to picomolar resolution.

It reads the free, bioactive cortisol in your sweat, the same fraction a lab measures in serum, which is why a Curve reading tracks a blood draw closely in bench testing.

  • 1 pmol/L resolution on free cortisol.
  • Matched control electrode cancels sweat and motion noise.
What it costs to keep reading

Less than a coffee a week.

One 4-pack lasts about eight weeks, so a year of continuous cortisol runs roughly six to seven packs. Subscribe & save makes it cheaper and automatic.

Plan
Per 4-pack
About / year
One-time 4-packs
CA$29
~CA$190
Subscribe & save
CA$24
~CA$156

Estimated at ~6.5 packs a year of continuous wear. Skip, pause, or cancel a subscription any time.

Never run out

A fresh 4-pack arrives before your last sensor expires. Your curve never goes dark.

17% cheaper, automatically

Subscriber pricing is locked in. No codes, no re-ordering, no thinking about it.

Total control

Skip a shipment, change the cadence, or cancel from the app in two taps. No phone calls.

In every 4-pack

Eight weeks, in one small box.

New here? You'll need the band.

Sensors read; the Curve band is the brain that turns them into your continuous curve. Founder bands include your first 4-pack.

Shop the Curve

Sensor questions.

How do I know when to swap a sensor?

The app counts each sensor down and nudges you a day before it expires at 14 days. Swapping takes about ten seconds and your curve continues without a gap.

Is sweat cortisol the same as blood cortisol?

Sweat carries the same free cortisol fraction as a blood draw, the bioactive form your body responds to. In bench testing, Curve's readings stayed within about 8% of a serum lab reference over 14 days of wear.

How long do unopened sensors last?

Sealed sensors keep for about 12 months at room temperature. Subscribe & save sends just enough so your spares are always fresh, rather than stockpiling.

Can I pause or cancel a subscription?

Any time, from the app, in two taps. Skip a shipment, stretch the cadence, or cancel outright, no calls and no fees. You keep founder pricing as long as the subscription stays active.

Do these fit the future hormone bands?

The cortisol sensor fits every Curve band. Testosterone, estradiol, and melatonin arrive as their own sensor modules through 2028, and subscribers get first access to each.

Reserve early access

Lock in founder sensor pricing.

Reserve your Curve and your sensor plan ships with it in Q4 2026. We only charge when it ships, never before.

Subscribe & save4-pack auto-ship, every 8 weeks.
CA$24per 4-pack
One-time 4-packNo commitment, reorder any time.
CA$29per 4-pack
Founder bonusFirst 4-pack free with a band.
Included
Founder pricing locked for year one

No deposit. No spam. Leave any time.

Prices shown are target prices and may differ from the final sale price.