Key4U Patient Diary App

The Key4U mobile application or K-app is a digital diary designed to help you with your MSD treatment for cancer with tracking symptoms, taking notes, accessing information about the specific treatment and allowing navigation to useful links which offer additional support.

This application also allows you to send reports to your medical team easily so they can regularly monitor how you're feeling.


Please note, the app is intended for patients on a specific MSD treatment and you will need a registration code before you can start using it so please ask your healthcare professional for this.

Download this application today to start exploring it.


This mobile application is intended for use in South Africa only.

Further information can be found in the terms of use in the app.

Further information on our data protection measures can be found on our company privacy page at www.msd.co.za.

If you wish to report an adverse event related to a specific MSD product, please email us at DPOC dpoc_zaf@merck.com.

For any technical difficulties or support relating to the Key4U app, please send an email to support_pcs@msd.com.*

*Please note, this email address is monitored and managed by a third party provider.

This mobile application has been developed and is owned by Merck Sharp & Dohme (South Africa) Limited ("MSD").