The Jersey Shore star, 24, who gave birth to Lorenzo Dominic LaValle on Aug. 26, showed off her trim post-baby body in an Instagram photo taken over the weekend, as she posed with friends before a night out.
Polizzi credits breastfeeding for helping her slim down.
"I've lost a lot of my baby weight! Also it's the best for him!" she wrote on Twitter last week.
Still, it's not exactly life as usual for the Polizzi, who's now starring in the MTV spin-off Snooki & JWOWW. She's been up early every day to attend to her little boy, and is posting pic after pic of him online.
Even at just a month old, "He's growing up too fast," she writes.