mySugr

Is mySugr safe?

Mostly, yes, for the kind of app it is. mySugr is a diabetes logbook that Roche bought in 2017, and it shows no ad tracking on Apple's privacy label, keeps data on servers in Frankfurt (or in the US for American users), and lets you export or delete everything from inside the app. The weak points are elsewhere. Your health readings feed Roche's own analytics, accounts have no two-step login that we could find, and in July 2024 a bug in the paid bolus calculator could suggest too much insulin.

We score mySugr 70/100, just behind Abbott's FreeStyle LibreLink (71) and ahead of the Dexcom G7 app (67).

What mySugr collects

Apple's label lists health and fitness data, precise location, contact details, photos, identifiers and diagnostics as linked to you for running the app. Three lines matter more. Health data, identifiers and app use are linked to you for analytics; your user and device IDs are used to personalise the product; and your name and email are used for Roche's own marketing. There is no "Data Used to Track You" section, so the label does not show tracking across other companies' apps. Location is optional: you can tag log entries with GPS or type a place.

On Google Play, mySugr says it may share your name, address, phone number, health and fitness data and messages with other companies, mostly for app functionality. That fits the privacy notice, which names Amazon Web Services for hosting, Google's Firebase Crashlytics for crash reports, Salesforce for support and marketing, Braze for in-app messages and Qualtrics for surveys.

Roche's notice, in force since 1 June 2025, covers mySugr together with the Accu-Chek SmartGuide apps. mySugr GmbH in Vienna and Roche Diagnostics International in Switzerland are joint controllers. Product-improvement analysis and marketing that uses your health data both need your opt-in consent. Research is the exception. Roche may analyse pseudonymised data under its "legitimate interests", and you can object only by emailing customer service. It may also share de-identified or aggregated data with other companies for research.

Is my mySugr data secure?

Roche says account data sits in the Roche Diabetes Cloud, which encrypts it, and mySugr's help pages say the service is HIPAA compliant in the US. Roche runs an invite-only bug bounty on HackerOne that pays for serious findings, and its scope lists mysugr.com. Accu-Chek hardware is excluded. We found no reported breach of mySugr accounts.

What we did not find is two-step login. You sign in with an email and password, and an email code confirms the address only when you sign up. For an account that holds years of glucose, insulin and weight records, that is the main gap. We also found no published security audit or certificate for the app; mySugr's ISO 13485 certification is about medical-device quality, not security.

The 2024 bolus calculator bug

The bolus calculator is a Pro feature for adults that suggests an insulin dose from your glucose, carbs and settings. During internal tests on 16 July 2024, mySugr found that on iPhone, for users who log in mmol/L, an insulin correction factor could be applied wrongly in rare cases. The suggested dose could then be higher than intended. mySugr said a very low wrong factor "may lead to a serious incident" if the dose is injected. The bug had been there since version 3.0.0 of the calculator. mySugr fixed it in app version 3.99.1 and sent an urgent field safety notice, filed with Germany's medicines regulator BfArM on 29 July 2024, asking users to update and re-check their settings.

We found no report of harm and no regulator order. But it is the main reason scams and harmful content sits at 70 rather than higher: in an app with no strangers, a wrong dose suggestion is the real risk. Apple rates the app 16+ for frequent medical treatment information, while Roche's terms require users to be 18, a small gap that also costs points.

Changes coming to your account

Roche is moving mySugr users to a single Accu-Chek account that also works for its SmartGuide CGM apps and clinic tools. The move is optional for now, but mySugr says it will become mandatory. On 29 June 2026 mySugr also retired Pump Control, the feature that ran the discontinued Accu-Chek Insight pump from the app. Past pump data stays in the logbook.

Phishing is the practical risk during a migration like this. mySugr's own advice is to check that emails about your account come from [email protected].

How to use mySugr more safely

1. Check the bolus calculator settings after every major update, and agree any change with your diabetes team.
2. Use a long, unique password, since there is no second login step.
3. Leave product-improvement and marketing consent off if you do not want your logs used that way; you can withdraw both in account settings.
4. Email [email protected] to object to research use of your data.
5. Export a CSV or PDF report before you delete your account, then cancel any Pro subscription and use Delete Account in settings.

How we scored it

The regulatory record (86) is the strongest factor: no privacy fine or order, with the 2024 field safety notice counted as context. Privacy (64) is the weakest, because health data is linked to you for analytics and research use runs unless you object. Security (68) has a paid bug bounty and no known breach but no two-step login, and transparency and control (76) gains from in-app export and deletion.