"I had a couple of awkward stages," the 24-year-old Vampire Diaries star told E! News at the Trevor Live benefit for the LGBT youth hotline The Trevor Project at the Hollywood Palladium Sunday.
"Now we have hair and makeup. I pay professionals. But you didn't have professionals when you were grade three."
Nina said she started getting teased in elementary school after she got a particularly unflattering haircut.
"I had a chunky face," she went on. "I had a phase where I cut my hair like a boy. Kids will find anything to pick on you for whether it's true or not because it makes them feel better and bigger and it isn't until you're the victim that you realize that it's not fun and it's not cool. Until you learn, you can hurt a lot of people."
Founded in 1998, The Trevor Project provides crisis intervention and suicide prevention services to lesbian, gay, bisexual, transgender and questioning young people ages 13-24.
"The Trevor Project has helped so many people save lives and hopefully it will continue to save more," Nina said of the organization.