https://www.theguardian.com/technology/2019/dec/14/facebook-prep-anti-hiv-drug-misinformation

Advocates fear such ads could roll back decades of hard-won progress against HIV/Aids and are calling on Facebook to change its policies

Since late summer, many LGBTQ+ Facebook users’ newsfeeds have begun to display medically incorrect targeted advertising. These ads pertain to Truvada, a one-pill-a-day pharmaceutical that has been demonstrated to reduce the likelihood of HIV transmissions by as much as 99%, making it a key mechanism in the decades-long fight against HIV/Aids.