A randy robber stole 19 boxes of condoms from a Bronx drug store and slashed the security guard who tried to stop him, according to police.

The thief, about 35, loaded a bag with the contraceptives at a Rite Aid at 3012 Third Ave. in Melrose Tuesday at 10 a.m. and then tried to leave without paying.

A security guard tried to thwart the theft, but was attacked with a box-cutter. He suffered minor injuries.