The Data Protection Commission is warning Irish people to check what an app will do with their personal information before downloading it.
It comes after a top US politician called on the FBI to investigate FaceApp, which has returned to popularity online this week.
The app allows people to change their selfies to make themselves look older or younger.
The top Democrat in the US Senate Chuck Schumer wants an FBI investigation into the app – because it is owned by a Russian company and requires users to give it control over huge amounts of the personal information stored on your device – including your name, image and likeness.
Newstalk Tech Correspondent Jess Kelly said the terms and conditions attached to the app are extensive – but very similar to those included with many social media apps.
“If you have the Facebook app on your phone; if you have Instagram; if you have any social media platform on your device, the same fears are in place.
“All it takes is one hacker to get access to their servers and your information is compromised.”
FaceApp claims to have more than 80 million active users.
It has denied selling or sharing user data with third parties and has insisted most images are deleted from its servers within 48 hours of upload.
Graham Doyle, Head of Communications for the Data Protection Commission said users should never sign up to an app unless they are satisfied with how their personal data will be used.
“The Data Protection Commission would advise individuals who are considering signing up to any app to firstly check what happens to their personal data and to make sure that they do not provide any personal information until they understand and are satisfied with how this information will be used," he said.
FaceApp was launched in 2007 and has hit the headlines in the past – notably when it was accused of creating a racist filter.