The US star, 26, recently wed British comic Russell Brand, 35, in a spiritual ceremony in India and said she feels the difference already in her life.
She said to Access Hollywood: 'I think everybody feels different after they're married. I think they feel completion. I feel good. I feel stress free.'
Perry added that you won't hear any details of their private wedding from her or her new husband.
She said: 'I made a promise to [Russell] and he made a promise to me and we have to keep that promise. That's one of the things that we keep private - our relationship.
'We've just kind of taken a step back because we put so much of ourselves out there professionally.'