Flo is the world's most downloaded period tracking app, with over 380 million installs and 60 million monthly active users. It's also the app that brought period tracker privacy into mainstream conversation — not because of what it got right, but because of what went wrong.

If you're looking for a Flo alternative that takes your privacy seriously, this guide breaks down the five best options available in 2026.

Why People Are Leaving Flo

The FTC Settlement

In January 2021, the Federal Trade Commission charged Flo Health with deceiving users about its data practices. The FTC found that Flo shared sensitive health data — including information about users' periods, pregnancies, and fertility — with third-party companies including Facebook and Google.

Flo had explicitly promised users that their health data would remain private. The company's privacy policy stated that health information would not be shared for advertising purposes. The FTC found this was false.

The resulting settlement required Flo to:

Obtain users' consent before sharing health data
Instruct third parties to destroy previously shared data
Undergo independent privacy audits for 20 years

The Anonymous Mode Controversy

After the U.S. Supreme Court overturned Roe v. Wade in 2022, Flo rushed to launch "Anonymous Mode." The feature was marketed as a way to use the app without any personally identifiable information. However, security researchers quickly pointed out several concerns:

Anonymous Mode doesn't encrypt existing data retroactively
Metadata (IP addresses, device identifiers) may still be collected
The feature requires users to actively opt in — most won't
Flo's numerous third-party SDKs may still collect data independently

The Broader Problem

Even setting aside the FTC case, Flo's business model creates an inherent tension. The free version is ad-supported, meaning Flo's paying customers are advertisers, not users. When your revenue depends on advertising, there's a structural incentive to collect and share as much user data as possible.

Flo Premium costs $9.99/month or $49.99/year, but even premium users don't fully escape tracking — the app still contains numerous third-party SDKs for analytics and attribution.

The 5 Best Flo Alternatives

1. Cythr — Best Free Alternative

Price: Free | Platform: iOS, Android | Best for: Full-featured tracking without the privacy trade-offs

Cythr is the closest thing to a direct Flo replacement that doesn't compromise on privacy. It offers cycle tracking, symptom logging, predictions, and AI-powered features — all for free, funded by an optional donation model.

What it does better than Flo:

No advertising or third-party analytics SDKs
AES-256 encryption for all health data
AI Smart Log powered by Anthropic's Claude, with data processed ephemerally (nothing stored by the AI provider)
Goal-dependent interface that adapts for conception, contraception, or general health tracking
Full GDPR compliance with one-tap data export and deletion

What Flo does better:

Larger community and content library
More established prediction algorithms (though Cythr's AI-driven approach is rapidly improving)
Partner-integrated features (Flo has been around longer)

Bottom line: If you want everything Flo offers but without the privacy concerns and the subscription fee, Cythr is the most compelling alternative.

2. Clue — Best for Scientific Rigor

Price: Free (basic), $9.99/month (Clue Plus) | Platform: iOS, Android | Best for: Users who value evidence-based health information

Clue, developed by a Berlin-based company, has built its reputation on scientific credibility. The app collaborates with research institutions including Oxford, Columbia, and Stanford, and presents cycle information backed by peer-reviewed research.

What it does better than Flo:

GDPR-compliant by default (German jurisdiction)
Published transparency reports
Evidence-based health content reviewed by medical professionals
No gamification or "pink it and shrink it" design choices
Clean, gender-neutral interface

What Flo does better:

More feature-rich free version
Pregnancy tracking mode
Larger content library

Limitations:

Clue Plus is expensive at $9.99/month
Some advanced features locked behind paywall
Uses some third-party analytics (though less than Flo)

3. Stardust — Best for Younger Users

Price: Free (basic), $4.99/month (premium) | Platform: iOS, Android | Best for: Users who enjoy astrology-themed wellness

Stardust gained massive popularity after the Dobbs decision, with over 3 million downloads in a single weekend. The app combines cycle tracking with astrology and cosmic themes, appealing primarily to Gen Z and younger millennial users.

What it does better than Flo:

Claims end-to-end encryption (implemented after 2022 backlash)
Engaging, unique aesthetic
Community features with privacy controls
Lower subscription cost

What Flo does better:

More comprehensive health tracking
Better prediction accuracy
More established medical content

Limitations:

History of data-sharing before the 2022 overhaul
Privacy practices improved but not independently audited
Astrology focus may not appeal to all users
Less comprehensive symptom tracking

4. Natural Cycles — Best for Contraception

Price: $12.99/month or $99.99/year | Platform: iOS, Android | Best for: Users seeking an FDA-cleared contraceptive method

Natural Cycles is the first and only FDA-cleared contraceptive app. If your primary goal is using cycle tracking for birth control, Natural Cycles offers clinical validation that no other app can match.

What it does better than Flo:

FDA De Novo classification as a contraceptive
Clinically validated algorithm with published Pearl Index data
Basal body temperature integration for biological (not just statistical) predictions
Clear regulatory framework

What Flo does better:

Significantly cheaper (Flo free vs. Natural Cycles $99.99/year)
Broader feature set beyond contraception
No thermometer required

Limitations:

Expensive at $99.99/year
Requires daily basal body temperature readings
Not designed for general cycle awareness
Extensive data collection (necessary for contraceptive function)
Data stored on cloud servers

5. Drip — Best for Maximum Privacy

Price: Free | Platform: iOS, Android | Best for: Users who want absolute local-only data storage

Drip is the opposite of Flo in every way. It's free, open-source, community-developed, and stores absolutely nothing in the cloud. Every data point stays on your device. There are no accounts, no servers, and no company that could be compelled to hand over your data.

What it does better than Flo:

Fully open source (code is auditable)
100% local data storage
No accounts, no servers, no cloud
Zero third-party dependencies
Community-developed with no profit motive

What Flo does better:

Vastly more features
Better predictions
Cloud backup and sync
Community features
Regular updates

Limitations:

No cloud backup (lose your phone, lose your data)
Very basic prediction algorithms
Minimal UI/UX polish
Limited symptom tracking options
No AI or advanced features

Feature Comparison: Flo vs. the Alternatives

Feature	Flo	Cythr	Clue	Stardust	Natural Cycles	Drip
Price	Free/$9.99/mo	Free	Free/$9.99/mo	Free/$4.99/mo	$99.99/yr	Free
Privacy Score	4.5/10	9.5/10	7.5/10	7.0/10	6.5/10	9.0/10
AI Features	Basic	Advanced	None	Basic	None	None
Cycle Predictions	Good	Good	Good	Fair	Excellent	Basic
Symptom Tracking	Extensive	Extensive	Extensive	Moderate	Limited	Basic
Contraception Mode	No	Yes	No	No	FDA-cleared	No
Conception Mode	Yes	Yes	No	No	Yes	No
Open Source	No	Partial	No	No	No	Yes
Ad-Free	Premium only	Yes	Premium only	Premium only	Yes	Yes

How to Switch from Flo

If you've decided to leave Flo, here's what to do:

1. Export Your Flo Data

Go to Flo Settings > Account > Request My Data. Flo is required to provide your data under GDPR (regardless of where you live, thanks to the FTC settlement terms). The export may take up to 30 days.

2. Delete Your Flo Account

After exporting, go to Settings > Account > Delete Account. This initiates a permanent deletion of your data from Flo's servers.

3. Check Third-Party Data

Remember that Flo shared data with Facebook and Google before the FTC settlement. Consider:

Reviewing your Facebook ad preferences and off-Facebook activity
Checking your Google ad personalization settings
Using a privacy-focused browser extension to block health-related ad targeting

4. Set Up Your New App

Most Flo alternatives allow you to import basic cycle data. You'll need at least your last 3 period start dates for accurate predictions. If you have more historical data, predictions will be better.

The Bottom Line

Flo isn't inherently a bad app — it has good features, a large community, and its predictions have improved significantly over the years. But its privacy track record is objectively poor, and its ad-supported business model creates ongoing conflicts of interest.

The good news is that in 2026, you don't have to choose between features and privacy. Apps like Cythr prove that it's possible to offer a full-featured, AI-powered cycle tracker without monetizing user health data.

Your menstrual cycle data is yours. Choose an app that agrees.

This article reflects information available as of March 2026. App features and privacy policies change regularly. Verify current practices with each app directly.