A period tracker knows a lot about you: when your cycle starts, how you feel, and sometimes whether you’re trying to get pregnant. That makes period tracker app privacy worth a few minutes of your time. Here’s the short answer: Flo, Clue, and Stardust are all popular and free to download, but their App Store privacy labels differ a lot. Here’s what each one says it collects, and a quick word on what a health app is and isn’t required to protect.
Period tracker apps at a glance
I compared each app’s App Store and Google Play listing. Ratings and prices are as of October 2026 and can change. I’m a health writer, not a doctor, and none of these apps diagnoses or treats anything.
| App | Price | Rating | Health data on its App Store label |
|---|---|---|---|
| Flo | Free; Premium plans in the app | 4.74 on App Store (2M); 4.72 on Google Play (5.1M) | Health and fitness data and sensitive info are linked to you |
| Clue | Free; Clue Plus from $9.99/month | 4.76 on App Store (405K); 4.48 on Google Play (1.5M) | Health and fitness data and sensitive info are linked to you |
| Stardust | Free; paid plans in the app | 4.76 on App Store (119K); 4.53 on Google Play (23K) | Health and fitness data is listed as not linked to you |
Period tracker app privacy: what each app says it collects
Apple requires developers to describe what their apps collect, and Google asks for a similar “Data safety” section. Apple doesn’t verify these labels, so they show what the developer says.
Flo
Flo is made by Flo Health. Its App Store label lists data used to track you (purchases, location, identifiers, and usage data). It also lists as linked to you: health and fitness, purchases, location, contact info, user content, search history, identifiers, usage data, sensitive info, and diagnostics. The App Store shows several Premium prices, from $1.99 to $59.99, so read the plan before you subscribe.
Download it from the App Store or Google Play.
Clue
Clue is made by BioWink GmbH. Its App Store label lists identifiers as used to track you, and health and fitness, location, contact info, user content, identifiers, usage data, and sensitive info as linked to you. The App Store lists Clue Plus at $9.99 for one month and $39.99 for 12 months.
Download it from the App Store or Google Play.
Stardust
Stardust is made by Stardust App LLC. Its App Store label lists purchases, identifiers, and usage data as used to track you, and lists health and fitness, purchases, identifiers, and usage data as not linked to you. Paid plans are sold in the app, with several price points listed on the App Store.
Download it from the App Store or Google Play.
A quick word on privacy law
Many people assume a health app is covered by HIPAA, the federal health privacy law. In most cases it isn’t. The U.S. Department of Health and Human Services says that HIPAA doesn’t apply to health information that an individual enters into a mobile app offered by an entity that isn’t regulated by HIPAA. That’s why the app’s own privacy policy matters so much. You can read HHS’s guidance on online tracking technologies.
The FTC also took action in the Flo case. In January 2021, the FTC said Flo Health settled allegations that it misled users about how it shared their health data, and the order required Flo to get users’ consent before sharing personal health information. The order was finalized in June 2021. That case shows why it’s worth reading the label and the policy.
How to protect your cycle data
- Read the App Privacy label on iPhone or Data safety on Google Play before you install
- Use a separate email address for the app, and don’t share more details than you need
- Turn off ad personalization and location in your phone’s settings if the app doesn’t need them
- Lock the app with a passcode and use a strong phone passcode
- Skip optional questions, like notes, mood, and symptoms, if you don’t want them stored
- When you stop using the app, delete your data and your account, not just the app
- Consider a paper calendar if you want zero data online
For more health apps, browse our health and fitness app guides and our free app picks.
Frequently asked questions
Which period tracker is the most private?
It depends on what you share. On the App Store, Stardust lists health data as not linked to you, while Flo and Clue list health data as linked to you. Labels are self-reported, so read each app’s privacy policy too.
Can a period tracker app share my data with advertisers?
Some apps list data used for tracking or advertising on their labels. Check the label and your phone’s ad settings, and limit what you enter.
Do I need to pay for a period tracker?
No. The free versions track your cycle. Paid plans add extras, so pay only for features you’ll use, and note the renewal date.
How do I delete my data?
Look in the app’s settings for an option to delete your account or data. Deleting the app alone may not delete what’s stored on the company’s servers.
Bottom line
- Check the label first: the three apps differ in what they list as linked to you.
- Share less: skip optional questions and use a separate email.
- See your doctor: for pain, very irregular cycles, or family planning, an app isn’t enough.
Pick the app whose privacy label you’re most comfortable with, and review it again every few months. Labels, prices, and policies change, so check the store listing before you subscribe.
