Meta's release this week of an AI feature that let people alter Instagram content drew swift blowback.
Regulators say features such as infinite scroll contribute to "compulsive use" and "unhealthy habits".
The tech giant said people can opt out - but privacy campaigners called it a "recipe for disaster".
The order comes days after the BBC published an investigation about the platform showing such ads to users.
The ads use terms including “rape” and “child video” and link to content on the messaging app Telegram.
A feature in Meta's glasses which boosts the voice of people will be capped at three hours for free use.
WhatsApp says the feature is not yet live and that it has built in safeguards against potential scams and impersonation.
WhatsApp is set to let people chat without having to reveal their phone number - by exchanging unique usernames instead.
