Facebook's ad sales team is hitting up the drug industry.
On Thursday, the company's New York-based health unit hosted an invitation-only breakfast for pharmaceutical marketers to learn about targeting users for their clinical trials.
CNBC viewed a copy of the invitation, which asked participants to attend a presentation on the company's "new clinical trials strategy."
Facebook is already widely used by clinical trial recruiters. The sector is a massive revenue opportunity for the company. Research firm eMarketer estimates that pharma and health-care marketers will spend $3.1 billion on digital advertising by 2020, up from $1.9 billion last year.
According to a person who attended Thursday's event, Facebook detailed how drug marketers can and can't target users. The source requested anonymity because Facebook did not make the details public.