Privacy
Is 28 Private? Your Period and Health Data, Explained
Plain answers about your data in 28: what we collect, what we never do, who we share with, and how to delete everything.
Last reviewed
The short version
- There are no ads in 28, and we don't sell your data.
- We don't use your health data for advertising.
- You can delete your account and its data at any time, in the app under Profile or by emailing support@28.co.
- Apple Health, Health Connect, Oura and partner sharing are optional and can be disconnected anytime.
The full details are in our privacy policy.
Common questions
- Does 28 sell my data?
- No. There are no ads in 28, and we don't sell your data.
- Does 28 share my period data with advertisers?
- No. We don't use your health data for advertising, and we don't share your personal information for targeted advertising. On iOS (version 2.3.1 and later), the app includes AppsFlyer for install attribution through our OneLink (https://28.onelink.me/TXCT). That tells us which link or campaign led to a download. On account creation, the attribution fields (media source, campaign, ad group, channel and sub parameters) are synced to RevenueCat.
- Where is my data stored?
- Your account and health data are stored with our database provider in the United States. Your data is encrypted in transit and at rest.
- Can I use 28 without connecting other health apps?
- Yes. Apple Health, Health Connect, Oura and partner sharing are optional, and you can disconnect them at any time.
- How do I delete my data?
- Delete your account in the app under Profile, or email support@28.co. Your account and health data, including cycle history, journal, temperatures, meals and chats, are deleted from our database. Copies in encrypted backups are overwritten after about 30 days. A few records are kept, such as purchase records and support conversations, as our privacy policy explains.
- Does 28 respond to law-enforcement requests for reproductive data?
- We don't volunteer member data to any government, and we don't honor informal requests. Anyone asking for member data must present valid legal process, and where the law lets us require a warrant or court order, we do. We challenge demands that are overbroad or improper, and if a court compels us, we hand over the narrowest set of data possible. Where the law allows, we tell you before we comply.
- Is Gaia, the AI companion, trained on my chats?
- Gaia runs on models from OpenAI, with Anthropic as a backup, and Google for recipe and meal imagery. We use OpenAI and Anthropic through their business APIs, which don't use customer data to train their models. Google receives meal and recipe descriptions and images only, and does not receive your identity or cycle data. If you talk to Gaia by voice, the audio goes to OpenAI or xAI in real time, and we don't record or store it.