Kristin Cavallari is highlighting her Uncommon Beauty skincare line with a series of new photos on Instagram, featuring the reality star in a black string bikini. Cavallari, 39, posed in swimwear to promote her brand's Enhanced Pineapple Peptide Nectar.

In the images, Cavallari is seen by a sheer white curtain with a waterfront view. One photo captures her facing the camera with her hand on her hip, while another shows her leaning against the curtain with her eyes closed and an arm raised. She captioned the post, "Tan lines, vitamin C + peptides 🍍☀️."

Kristin Cavallari poses from the side in a black string bikini beside a sheer white curtain.

A close-up shot features Cavallari beside a palm tree, holding a bottle of the Enhanced Pineapple Peptide Nectar. She continued to wear the black bikini in this image.

Kristin Cavallari holds a bottle of Uncommon Beauty Enhanced Pineapple Peptide Nectar while posing beside a palm tree in a black bikini.

These photos follow Cavallari's participation in Miami Swim Week for Uncommon James' inaugural runway show. In June, she discussed her preparation for the event on her podcast, "Let's Be Honest." Cavallari detailed a more disciplined approach in the month leading up to the show, including significantly reducing alcohol consumption and focusing on her fitness routine. She mentioned aiming for four workouts per week, incorporating weight training and StairMaster sessions.

Cavallari also spoke about managing a torn labrum, which impacted her ability to train her legs. She suggested that this physical limitation may have contributed to a leaner appearance for the runway show. Despite her preparation, Cavallari admitted to feeling nervous before walking the runway, describing the experience as a significant personal and professional milestone.