Lili Reinhart's acne is her ''biggest insecurity''.

The 'Riverdale' star has opened up about her battle with the skin condition in the hope it inspires other people to speak out too.

She shared in a series of posts on her Instagram story: ''I have a cystic breakout on my forehead currently. And I had to do a photo shoot all day long. I've had cystic acne since I was 12. And it has caused major self-esteem issues ever since. I had to put my biggest insecurity on display. There was nowhere to hide. 20+ people were studying my face on the camera monitor at any given time during the 11 hour shoot. And all I could think about when I was in front of the camera were the pimples on my forehead. I had to put my biggest insecurity on display. There was nowhere to hide. 20+ people were studying my face on the camera monitor at any given time during the 11 hour shoot. And all I could think about when I was in front of the camera were the pimples on my forehead.''

And the 21-year-old actress wants to ''normalise'' the condition so that others who are struggling are no longer ''embarrassed or ashamed''.

She added: ''I feel the need to talk about my struggle with acne. Because maybe if I normalise my broken-out skin, more people ... including myself ... will be able to feel okay about their skin. My breakouts don't define me. To anyone out there who feels embarrassed or ashamed by breakouts ... I feel you. We have each other. So let's get through this acne experience together.''