The company has started to roll out changes due to concern over exploitation amid the coronavirus outbreak, and the social media network's director of product management has confirmed the rollout.
He tweeted: "We're banning ads and commerce listings selling medical face masks.
"We're monitoring COVID19 closely and will make necessary updates to our policies if we see people trying to exploit this public health emergency. We'll start rolling out this change in the days ahead."
In a blog post, Facebook later added: "We are temporarily banning advertisements and commerce listings, like those on Marketplace, that sell medical face masks. We'll begin to enforce this change over the next few days.
"We already prohibit people from making health or medical claims related to the coronavirus in product listings on commerce surfaces, including those listings that guarantee a product will prevent someone from contracting it.
"We also have a dedicated channel for local governments to share listings they believe violate local laws.
"Our teams are monitoring the COVID-19 situation closely and will make necessary updates to our policies if we see people trying to exploit this public health emergency."