Looking stunning in a bright purple bodycon Zac Posen dress the star attended the Nordstrom pop-up event in Greeley Square Park, New York where she posed for snaps with her signature scent, encased in a purple glass bottle shaped like a cat.
Katy told Just Jared: "I love all the types of scents that I incorporated in it. It has a bit of gardenia, citrus, jasmine which I love, and then it has sandalwood which makes it a bit ambiguous and different for me.
"I didn't want it to be a complete knock-off of my favourite scents, so that meant there was a year and a half of me testing and basically me going into the labs in NYC where all the chemists are. It looks like a science class down there! I would ask for different things and quantities of it. I was very involved."
Katy is the latest in a long line of celebrities to launch their own fragrance. Last month saw the launch of Kim Kardashian's signature scent.