Last updated June 6, 2026
We collect female cycle start registrations to run the app and generate cycle forecasts. We will never sell this data. You can delete your data or your account at any time. If you have any questions or suggestions on how we can improve privacy, email us at [email protected].
Lunarmates exists to help men understand and navigate the menstrual cycle with their partners. Women log their cycle so the app can track phases and make forecasts. The app processes those into forecasts so men can be more attuned, present and supportive. This requires us to handle intimate personal health data, and we take that responsibility seriously.
We do not sell your data. We do not build profiles. We believe meaningful privacy means collecting as little intimate health data as possible in the first place. The rest is only ever conjecture.
We are based in Denmark and data is stored in the EU under GDPR best practices. We have designed the service to be simple enough that there are very few third parties involved at all.
Please read this entire Privacy Policy to understand how we handle your data. If you have any questions, reach out to us at [email protected].
We process four types of data in order to provide our services on the Lunarmates app and the lunarmates.com website. All data is securely stored on servers located in the European Union (EU).
Account data: In order to create your Lunarmates account, we process your email address and your role (woman or man). We do not collect your name — accounts are pre-filled with the display name "Lunarmate" unless you choose to change it.
Usage data: In order to provide our services and technically improve performance, we process how you interact with our service. Such data includes device data (device model, identifiers, app version, crash reports and error logs), your IP address (used to deliver the service and determine approximate location for analytics and regulatory compliance), and general usage patterns. We do not collect your precise location or build profiles.
Health data: The only intimate health data point we collect from women is the period start date. We do not collect period duration, flow intensity, symptoms, mood, sexual activity, pregnancy intentions, or any other health information. From the start date alone, we compute the current cycle phase and generate phase forecasts for followers to see.
From men, we encourage the creation of personal notes and cycle-day observations that they choose to write within the app. These are used to personalise the experience so that the app works as intended — to help men track their own observations alongside cycle phases. Notes are private by default. Men may choose to edit and publish their personal notes as a post to the Forum. They do not have to publish under a real name — accounts are given the display name "Lunarmate" until they decide on another pseudonym or no name at all. That choice is theirs and they must actively change it from the default.
Notification data: We use push notifications and email reminders to keep cycle start registrations on track. With push notifications and/or email notifications enabled, a push subscription token is generated that we store on our server. If you receive email notifications, we use your email address for this purpose. We use these solely to send you service notifications from Lunarmates: men receive phase updates and period log reminders. We do not share push tokens with any third party beyond the browser push infrastructure, and we do not share your email address with any third party for notification purposes (see Section 3.1.1). You can manage notification preferences at any time in your account settings, or revoke push permission in your browser settings.
We do not sell, rent, or trade your personal data — including your health data — to any third party for money or other consideration, under any circumstances.
Data processing is essential to providing the Lunarmates service. Whenever you use our services, some personal and non-personal data is collected, stored, and analysed using internal and third-party tools.
Below are the purposes for which we process your data, and the type of data processed to fulfil each purpose.
To provide our service, we process the following:
We use a small number of third-party providers to help us deliver our core services.
Hetzner Online GmbH: Lunarmates uses Hetzner as our hosting provider. As a German company, Hetzner operates under EU law and GDPR. Our server is located in Helsinki, Finland (EU). All data is encrypted at rest and in transit. It is not possible to opt out of Hetzner as it is the infrastructure on which the entire service runs.
Brevo (Sendinblue SAS): Lunarmates uses services provided by Brevo to send push notifications, transactional emails (such as password resets and welcome emails), and service communications. Brevo processes your email address and device push token for this purpose. As a French company, Brevo operates under EU law and GDPR. You can read their privacy policy at brevo.com. It is not possible to opt out of Brevo entirely as it is a required tool to provide our service, but you can manage notification preferences in your account settings.
Browser push notification services: Push notifications are delivered via your browser's built-in push infrastructure. On Chrome this means Google's Firebase Cloud Messaging (FCM); on Firefox, Mozilla's push service; on Safari, Apple's APNs. We send only a minimal payload — the notification text — to these services. No health or identity data is included in any push notification payload. Each browser provider's own privacy policy governs how they handle delivery. We have no control over those providers' infrastructure and no visibility into delivery-side processing beyond what their respective privacy policies describe.
Sign in with Google (OAuth): If you choose to create your Lunarmates account or sign in using Google, we receive your email address from Google to create or authenticate your account. We do not store any Google display name — your account display name is set to "Lunarmate" regardless of sign-in method. Signing in with Google may involve a transfer of your data to Google servers outside the European Union. It is your choice whether to use this option; you may also sign up with an email address and password. No health data is shared with Google. You can manage privacy in your Google account settings at any time.
Third-party links: This policy references links to third-party websites such as those of our service providers. Once you leave lunarmates.com, this Privacy Policy no longer applies. We encourage you to review the privacy policies of any third-party sites you visit.
Legal basis: The legal basis for processing your account data and usage data is Art. 6(1)(b) GDPR (performance of a contract). The legal basis for processing health data is Art. 9(2)(a) GDPR (explicit consent), as follows:
I agree to Lunarmates processing the cycle data I choose to log in the app, so they can provide cycle forecasts.
Legitimate interests: We also process account data and usage data on the legal basis of Art. 6(1)(f) GDPR (legitimate interests) for the following purposes: identifying and fixing technical issues; monitoring app performance and security; preventing fraud and abuse; and analysing overall usage trends to improve the service. We carefully balance these interests against your rights and do not use health data for any of these purposes.
We use a single session cookie to keep you logged in. This cookie is essential for the app to function and contains only a cryptographically signed session identifier — it does not contain any health data or personally identifying information.
We do not use tracking cookies, advertising cookies, or any third-party cookies. We do not use browser fingerprinting. You can delete the session cookie by logging out, or by clearing your browser cookies. There are no consequences to deleting it beyond being signed out of the app.
If you contact us with questions about our service, we will communicate with you via email. We will access your account data to the extent necessary to help you. We do not share this data with third parties beyond what is necessary to respond to your request.
Contact: [email protected]
We may use anonymised and aggregated usage data to understand how the service is used and to improve it over time. No individual health data is used or shared for this purpose.
From time to time we may also invite users to participate in optional surveys, usability studies, and scientific research. Participation is always voluntary. If you choose to participate, we will use your responses solely to improve the service. We will never use survey responses to identify you individually or share them with third parties in identifiable form.
Legal basis: Art. 6(1)(f) GDPR (legitimate interests).
We may send you service-related communications including:
You can manage notification preferences in your account settings. Disabling notifications does not affect your core service access.
We may process and disclose personal data where required to do so by law, regulation, or valid legal process. We will carefully review all such requests to ensure they have a legitimate legal basis and are limited to the data that the requesting authority is authorised to access for the specific purpose stated. We will notify affected users where legally permitted to do so. The legal basis for any such disclosure is Art. 6(1)(c) GDPR (compliance with a legal obligation).
The Lunarmates Forum allows men to share observations and insights about cycle phases and days with the wider community of users. The following applies to Forum data:
Legal basis: Art. 6(1)(b) GDPR (performance of contract) for storing and displaying posts. Following account deletion, posts are fully anonymised and no longer constitute personal data under GDPR, as no link to an identifiable individual is retained. You may contact us at [email protected] to request removal of specific posts if you are unable to access your account.
Our server infrastructure is located within the European Union. Where we use third-party providers based outside the EU, we ensure appropriate safeguards are in place in accordance with GDPR Chapter V, such as Standard Contractual Clauses or adequacy decisions.
Business transfers: In the event of a merger, acquisition, sale of assets, or insolvency proceedings involving Mattrix ApS, your data may be transferred to a successor entity as part of that transaction. Before any such transfer is completed, we will give you at least two weeks' notice by email, including the name and details of the transferee and the privacy policy that will apply to your data after the transfer, giving you the opportunity to decide whether to keep your account under the new terms or delete your account and all associated data before the transfer takes effect. The legal basis for any such transfer is Art. 6(1)(f) GDPR (legitimate interests in preparing and conducting a business transfer).
We retain your data for as long as your account is active or as needed to provide the service.
You may request deletion of your cycle data at any time without closing your account, via the "Delete my cycle data" option in your account settings.
Account deletion and follow relationships:
When a woman deletes her account, the following applies immediately:
The follower will see an in-app notification on next login informing him that access has been removed and advising him of the 90-day window for his personal notes. No push notification is sent. Once account deletion begins it cannot be reversed. Full deletion from all systems, including backups, completes within 90 days.
Why notes are not exportable after a follow ends:
A man's personal notes are written in the context of following a specific woman's cycle at a particular time in her life. Once that relationship ends, those notes may contain sensitive observations. Out of respect for the woman's privacy, we do not allow those notes to be exported after the follow relationship is severed. The man retains read access for 90 days to allow him to review and manually record anything he considers his own personal information.
Forecasting pause: After 35 days have passed without a new cycle start being logged, the cycle forecasting function automatically pauses and returns no forecast. This does not prevent a follower from registering a cycle start — forecasting will resume as soon as a new cycle start is logged.
Under GDPR (Articles 15–22), you have the following rights regarding your personal data:
To exercise any of these rights, contact us at [email protected]. Under GDPR Art. 12, we will respond to all rights requests within one month of receipt. For complex requests, such as full deletion from backup systems, this may extend to three months, and we will inform you of the reason for any delay.
We implement appropriate technical and organisational measures to protect your data against unauthorised access, loss, or destruction. These include:
Despite these measures, no system is completely secure. If you believe your account has been compromised, contact us immediately at [email protected].
Lunarmates is not intended for use by children below the minimum age applicable in their country. The minimum age to use Lunarmates is:
We do not knowingly collect personal data from anyone below the applicable minimum age. If we become aware that a minor below the applicable threshold has created an account, we will delete their data promptly. If you believe a minor has registered, please contact us at [email protected].
Menstrual cycle data is health data under GDPR Art. 9. We treat it as such at every level of the service — technically, legally, and operationally.
Lunarmates does not collect data about sexual activity, pregnancy intentions, fertility goals, symptoms, mood, flow intensity, or any health information beyond the period start date itself. We collect the minimum necessary — one intimate health data point — and nothing more. Men's notes and observations are collected only with the intention to make the app function as intended and are never used for profiling or advertising.
Cycle data is something to protect. Knowing the timing of a woman's cycle may reveal things about her body, her rhythms, and her reproductive choices. That information deserves the same respect as any other private matter between people in a relationship.
We will never use cycle data to make inferences about pregnancy, fertility, or medical conditions beyond what is needed to generate the current cycle phase forecast. We will never share it with insurers, employers, or any government entity — except where compelled to do so by a binding legal order, in which case we will notify you to the extent permitted by law.
If you share your account credentials with another person, they will have access to your data. We strongly recommend keeping your login private. Women can revoke any follower's access at any time from their account settings without deleting their account.
If you use Lunarmates to log or record information about another person without their knowledge, you are responsible for ensuring that person is informed about this Privacy Policy and has given their consent beforehand. Logging another person's cycle data without their knowledge or consent is a serious violation of their privacy and of our terms and conditions.
We may update this Privacy Policy from time to time. When we do, we will update the "Last updated" date at the top of this page. For significant changes, we will notify you via email or in-app notification. Continued use of the service after non-material changes take effect constitutes acceptance of the revised policy. For material changes — particularly any affecting how health data is processed — we will seek explicit consent.
Reserved rights for future commercial activities: Lunarmates reserves the right in future versions of the service to introduce advertising, targeted advertising, third-party analytics cookies, commercial partnerships, affiliate programmes, or collaborations with brands and companies. Where any such change involves processing your personal data for new purposes — or sharing it with new categories of third party — we will treat it as a significant change, notify you in advance, and obtain any additional consent required under applicable law before your data is used for those purposes. We will never share your health data with commercial partners, advertisers, or affiliates without your explicit prior consent. Any introduction of advertising or data-sharing with commercial partners will require a separate, explicit opt-in consent — not a pre-ticked box, not a policy update notice, and not implied consent through continued use of the service.
The data controller for Lunarmates is:
Mattrix ApS Bymidten 65, 1tv 3500 Værløse Denmark [email protected]