Consumer health data
Your cycle data, and the laws that name it
A notice for residents of Washington, Nevada and Connecticut, published separately because those states ask for it separately.
Why this page exists
Washington's My Health My Data Act, Nevada's SB 370 and Connecticut's health-data provisions each ask companies that handle consumer health data to publish a notice specifically about it, separate from their general privacy policy. This is ours. If you are not in one of those states, nothing here is different from what our main privacy policy already says — this page is the same facts, arranged the way those laws ask for.
Who we are
- Anton Bondarenko, sole proprietorship (jednoosobowa działalność gospodarcza)
- ul. Chorzowska 51/53/21, 04-696 Warszawa, Poland
- NIP (tax ID): 9512542660
- onda@helloonda.com
What consumer health data is involved, and where it lives
Onda works from information about your menstrual cycle, which these laws treat as consumer health data. Your records are stored on your own phone: the date your last period started, the period dates and end dates before it, the period length worked out from them, your answers from setting up the app, your evening check-ins, and the plan the app builds from all of that. We never receive those records as such. With your consent, some values worked out from them do reach us — your phase, cycle day and cycle length, when you log a period, and the options you tap in the check-in — described below.
We want to be straightforward about a boundary these laws draw differently from how engineers usually think about it. The calculation that turns your period date into a cycle phase runs on your device, not on our computers. We do receive its results through analytics, as described below, so this notice applies to us in full.
Two kinds of consumer health data reach services we use. First, analytics. Onda is only offered with them on, so you agree to them on the app's first screen before you can use it: the phase you are in (and whether the luteal phase is early or late), your cycle day and your cycle length, sent with every usage event; an event each time you log a period starting or ending or change a period date; the options you tap in your evening check-in; and session recordings in which all text and images are hidden, the details of your cycle show as plain blocks, and the screens where you answer questions are not recorded at all — though which cards and buttons a screen shows can reveal where you are in your cycle, such as that your period is due, under way or late. While your birth control pauses your cycle, no phase is sent, so the events show that it does. These go to PostHog, in the European Union, filed under your Onda account's ID — a random code, not your name or email, but one we can match to your account. PostHog receives the IP address your phone connects from, as any server does; we have set it to discard the address on arrival and not to work out your location from it. Second, only if you turn reminders on: the schedule for your reminders and the text of each one. Because a reminder can say which phase you are entering, that text names a phase, and its timing can show when your period is due or a phase begins; it is stored against a send time and an account identifier. The dates you type and your daily plan are never uploaded as such — though together, the period events and your cycle day show your period dates.
Where it comes from
From you, and only from you. You type the date your last period started; everything else is worked out from it and from answers you give. Onda does not read Apple Health, Google Fit, your phone's calendar, a connected device, or any other app, and it does not buy or receive health data from anyone. You are its only source, and we intend to keep it that way.
What it is used for
- To work out which phase of your cycle you are in, and to build the day's training and food suggestions from that. This happens on your phone.
- To show you a forecast of the weeks ahead, and to place any dates you have marked within it. Also on your phone.
- To send a reminder at a useful moment, if you have turned reminders on.
- To see how Onda is used across the cycle and improve it — never for advertising. These are the analytics you agree to on the app's first screen.
It is not used for anything else. In particular it is never used to advertise or market anything to you, to build an advertising profile of you, or to decide what to charge you.
Your rights
If you live in Washington, Nevada or Connecticut you have the right to confirm whether we hold consumer health data about you and to see it; to have it deleted, including from anyone we shared it with; and to withdraw your consent to us collecting or sharing it.
The fastest route for the records on your phone is the app itself. Profile → Delete everything stops the app sending analytics, has our server ask PostHog to delete the analytics events and recordings filed under every ID this installation of Onda has used, deletes your account and clears any reminder schedule from our server, and erases everything on your phone. On your phone that takes effect straight away, with no waiting period and no undo; PostHog carries out deletions in a weekly batch, so its copy is gone within about a week. Reinstalling Onda starts new IDs, so for anything recorded by an earlier installation, write to us. The app tells you if PostHog, Appstack or RevenueCat could not be reached. Withdrawing your consent to analytics — Profile → Share usage and cycle data — does the same, because Onda is only offered with it on. Turning reminders off in Profile withdraws your consent to reminders alone, and deletes the schedule.
To make a request in writing instead — including to see what we hold, such as the analytics at PostHog — email the address at the top of this page, from your account's email address or, if you have not signed in, with the Analytics ID shown under Profile → What we store, so we can find it. We will respond within 45 days, and will tell you if we need a further 45 — which the law allows, and which we would rather not use. We will not charge you for a request. Be aware that withdrawing your consent to analytics means Onda can no longer be used, and deletes your data — see above.
If we turn a request down, you can appeal by replying to our decision. We will review it and write back within 45 days explaining what we decided and why. If we still say no, Washington residents may complain to the Washington State Attorney General at www.atg.wa.gov/file-complaint, Nevada residents to the Nevada Attorney General, and Connecticut residents to the Connecticut Attorney General.
Who can see it inside Onda
Only the people who run Onda. The consumer health data we hold is the analytics described above and, if you turned reminders on, your reminder schedule; access to the systems that store them is limited to the people who run those systems, and everyone with access is under a duty of confidentiality. We do not let processors access consumer health data beyond what they need to do the job described above, and we do not geofence anything, anywhere — least of all health facilities.
Changes
If we change how consumer health data is handled, we will update this page before the change takes effect, and we will ask for your consent again if the change needs it. Last updated: 1 October 2026.