Cycle OS ("the app", "the service") is operated by Cycle OS ("we", "us", "our"), based in the United Kingdom. By creating an account or using Cycle OS, you agree to these Terms of Service ("Terms"). If you do not agree, please do not use the app.
These Terms apply to the Cycle OS web app, any native app wrappers distributed via the Google Play Store or Apple App Store, and any associated services.
You must be at least 16 years old to use Cycle OS. By using the app, you confirm that you meet this age requirement. If we become aware that a user is under 16, we will delete their account promptly.
You must have the capacity to enter into a legally binding agreement and must not be prohibited from using Cycle OS under the laws of any applicable jurisdiction.
To access most features of Cycle OS, you must create an account using an email address or by signing in with Google. You are responsible for:
We reserve the right to suspend or terminate accounts that violate these Terms or that we believe have been compromised.
Cycle OS is a personal cycle tracking and wellness tool. The app provides:
We reserve the right to modify, suspend, or discontinue features at any time. Where possible, we will provide reasonable notice of significant changes.
🩺 Cycle OS is not a medical device, medical service, or substitute for professional healthcare advice.
The cycle predictions, phase information, and AI chat responses provided by Cycle OS are for general informational and personal tracking purposes only. They are not clinically validated, are not intended to diagnose any condition, and should not be used to make medical decisions — including decisions about contraception, fertility treatment, or reproductive health.
If you have concerns about your cycle, reproductive health, fertility, or any related health matter, please consult a qualified healthcare professional. Do not delay seeking medical advice based on anything shown in this app.
Cycle OS is particularly not suitable as a method of contraception. Cycle tracking alone is not a reliable form of birth control.
Your cycle data — period dates, moods, symptoms, journal entries, and all other health information — is stored securely in your personal account, encrypted at rest, and protected by Row Level Security so that only your authenticated session can access it. It is also cached locally on your device for offline use.
Your use of the app is also governed by our Privacy Policy, which explains in full how we handle your personal information. By using Cycle OS, you agree to the Privacy Policy.
The optional AI chat feature is powered by Anthropic's Claude API. When you use this feature:
Use of the AI feature is subject to Anthropic's own terms of service and usage policies.
You agree not to:
Violation of these rules may result in immediate account suspension or termination without notice.
All content, design, code, and materials in Cycle OS — including the name "Cycle OS", the app interface, text, graphics, and icons — are owned by Cycle OS and protected by UK and international intellectual property law.
You are granted a limited, non-exclusive, non-transferable licence to use the app for your personal, non-commercial use only. You may not copy, reproduce, distribute, or create derivative works from any part of Cycle OS without our prior written consent.
Your own user-generated content (journal entries, mood logs) remains your property. We make no claim over it.
We aim to keep Cycle OS available at all times, but we do not guarantee uninterrupted access. The service may be temporarily unavailable due to maintenance, updates, or circumstances beyond our control.
We reserve the right to:
To the fullest extent permitted by applicable law:
Nothing in these Terms excludes or limits our liability for death or personal injury caused by our negligence, fraud, or any other liability that cannot be excluded under UK law.
You may stop using Cycle OS at any time. You can request account deletion directly within the app via Me → Privacy & data → Delete my account & data, or by emailing admin@cycle-os.app with the subject "Account deletion request".
We may terminate or suspend your account if you breach these Terms. Upon termination, your right to use the service ceases immediately. Sections of these Terms that by their nature should survive termination (including Sections 5, 9, 11, and 13) will continue to apply.
These Terms are governed by and construed in accordance with the laws of England and Wales. Any disputes arising from these Terms or your use of Cycle OS will be subject to the exclusive jurisdiction of the courts of England and Wales.
We encourage you to contact us directly with any concerns before pursuing formal dispute resolution — most issues can be resolved quickly and informally.
We may update these Terms from time to time. When we make significant changes, we will update the "Last updated" date at the top of this page and notify you by email where appropriate. Your continued use of Cycle OS after changes are published constitutes your acceptance of the updated Terms.
These Terms, together with our Privacy Policy, constitute the entire agreement between you and us in relation to your use of Cycle OS and supersede all prior agreements, representations, and understandings between us. If any provision of these Terms is found to be unenforceable, the remaining provisions will continue in full force and effect.
Cycle OS Premium is available as a paid subscription with the following plans:
Free trial: A 7-day free trial is available for new subscribers. No charge is made during the trial period. If you do not cancel before the trial ends, your subscription will automatically begin and the applicable charge will be applied.
Payment: Payment is charged to your Google Play account at confirmation of purchase (or, if a free trial is offered, at the end of the trial period). By confirming a purchase you authorise Google Play to charge the applicable subscription fee to your account.
Auto-renewal: Subscriptions automatically renew at the end of each billing period (monthly or annual) unless you cancel at least 24 hours before the current period ends. Your account will be charged for renewal within 24 hours prior to the end of the current period at the then-current subscription price.
Cancellation: You can manage and cancel your subscription at any time via Google Play:
Cancellation takes effect at the end of the current billing period — you retain access to Premium features until that date.
Refunds: No refunds are given for partial billing periods. Refund requests are handled by Google Play in accordance with their refund policy (play.google.com/about/play-terms/index.html).
Price changes: Subscription prices may change from time to time. You will be notified of any price increase before it takes effect and given the option to cancel before the new price applies.