According to Facebook, end-to-end encryption is something they are working to bring to either service, but they note that it won’t be arriving this year and it will probably in 2022 when they roll it out. “While we expect to make more progress on default end-to-end encryption for Messenger and Instagram Direct this year, it’s a long-term project and we won’t be fully end-to-end encrypted until sometime in 2022 at the earliest.”
However, the company notes that they already introduced features like “Vanish mode” in Facebook Messenger and Instagram Direct that automatically vanishes after it’s been sent and read, although that is different from encryption because it means that should a message be intercepted, it can be read by the attacker.
In any case, if you do use Facebook Messenger or Instagram Direct, it’s not as if either platform is not secure, but if you value your privacy and security, then maybe you should seek a different messenger if you want to discuss more sensitive topics.