Anonymous Mode vs. VPNs: Which Actually Protects Your Period Data?

By Laure Lydon, VP of Security and Infrastructure

You've heard about VPNs for online privacy, and maybe you're wondering whether using a VPN is enough to protect your period-tracking data. The answer might surprise you. VPNs and Flo’s Anonymous Mode protect different things in different ways. Let me break down what each actually does and what you really need.

What VPNs Do (And Don't Do)

It’s important to understand what a VPN can — and can’t — do.

A Virtual Private Network (VPN) creates a secure, encrypted connection between your device and a VPN server. This helps shield your online activity from others.

Using a VPN can:

Hide your IP address — a number that can reveal your general location — from the websites and apps you use.
Prevent your Internet Service Provider from seeing the details of your browsing activity.
Protect your data when you’re connected to public Wi-Fi networks, like in cafés or airports.
Reduce the ability of websites to track your location based on your connection.

However, a VPN doesn’t make you fully anonymous online. It protects your data on its way to a website or app, but it doesn’t control what happens after it arrives.

It can’t limit what information you choose to enter into an app, how that app stores your data on its servers, or how your account details (like your email address) are connected within that service.

In short: a VPN secures the journey. What happens once your data reaches its destination depends on the app or website itself.

What Flo’s Anonymous Mode Does

Anonymous Mode works in a completely different way. It’s not about hiding your internet connection — it’s about separating your identity from your health data altogether.

When you use Flo in Anonymous Mode, your health information isn’t connected to who you are. That link simply doesn’t exist in our systems.

We protect your data at three key stages:

On your device: Your information is encrypted before it ever leaves your phone.
In transit: As it moves across the internet, it’s protected and routed in a way that keeps your identity separate. We use Cloudflare’s App Relay to help ensure your traffic can’t be tied back to you.
On our servers: Once it arrives, your health data remains anonymized and isn’t linked to identifying details.

In short: Anonymous Mode isn’t about masking your connection. It’s about designing the system so your identity and your health data aren’t connected in the first place.

You can read more here

Can You Use Both?

Yes — and in some situations, using both can make sense.

A VPN and Anonymous Mode protect you in different ways. A VPN hides your IP address and your internet activity while you’re online. Anonymous Mode makes sure your health data isn’t linked to your identity inside the app.

Used together, they create layered protection:

The VPN helps shield your connection.
Anonymous Mode separates your identity from your health information.

For period tracking specifically, Anonymous Mode provides the more important safeguard. Even if someone could see that you’re using a period tracking app (which a VPN can help conceal), they still wouldn’t be able to link your health data back to you when Anonymous Mode is enabled.

The Gist

VPNs and Anonymous Mode are designed to serve different purposes.

A VPN protects your internet connection. It hides your IP address and makes it harder for others to see your online activity.

Anonymous Mode protects something deeper: it separates your health data from your identity inside the app itself.

When it comes to period tracking — especially in a post-Roe environment or in places where reproductive health data may carry legal or personal risk — Anonymous Mode provides more meaningful safeguard. It’s built so your health information cannot be linked back to you, regardless of who might try to access it.

Your body. Your data.

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