The campaign comes after the high-profile case of three UK schoolgirls, who were caught on camera in February before they disappeared on their way to join ISIL in Syria.
British authorities say the students were among 43 girls and women who travelled to Syria over the past year and police are concerned that more may join the flow during the school holidays.
"I'd say to [any girl considering joining ISIL], please don't do it, you're being fed terrible lies by people who've manipulated and lured you into travelling to Syria," Metropolitan Police Assistant Commissioner Helen Ball told Al Jazeera.
"You might be being told you'll marry a fighter and help him in his work, but actually you'll become the sexual partner of someone you haven't chosen and I'm sure you'll be the victim of abuse."