The singer, who infamously used to wear a purity ring along with his brothers Joe and Kevin made the confession during an interview on US TV.
Speaking of his ring-wearing days, Nick said: "I don't regret it. I think it was an important part of my childhood.
"I think as I grew up, I sort of figured out what was important to me and my own belief system.
"We all grow up and we all live life and find out what's important to us, that's what happened.
"I went on that journey myself and I'm now comfortable with who I am and what I believe in and I'm an adult in all ways."
"Am I still a virgin? No, no. As I said, I'm an adult in all ways and comfortable with who I am."
Nick's brother Joe previously revealed that he stopped wearing his purity ring after losing his virginity at the age of 20 to Ashley Greene, while Kevin waited until he was married to wife Danielle in 2009.