THE PELTZMAN EFFECT APPLIES TO SEX, TOO: How PrEP, the pill to prevent HIV, may be fueling a rise in other STDs.

Even before PrEP hit the US market in 2012, there were fears that it would promote promiscuity, more risky sex, and unintended health consequences. The president of the AIDS Health Foundation called it a “party drug.” “Truvada Whore” emerged as a slut-shaming label for people who took it in the gay community.

Though some of those fears were tinged with moral judgement, there’s now data showing the concern about the health consequences is justified. A systematic review published in March in the journal Clinical Infectious Diseases found that some PrEP users are having more risky sex — and as a result, getting more sexually transmitted infections (STIs).

And also transmitting more sexually transmitted infections. But of course, the Peltzman effect applies everywhere.