
Heidi Zak is the Co-Founder and CEO of ThirdLove, a modern women’s essentials company. Zak dreamed of offering a better option—a “ThirdLove” where women wouldn’t have to choose between comfort and style. She is also committed to advancing more women in tech, and is an active angel investor in female-founded companies.

Q: What motivated you to start ThirdLove?
A: Back in 2013, there weren’t any underwear and bra companies that provided the product quality, online experience, and community that I was personally looking for, so I decided to create it. From ThirdLove’s unique half-cup sizing, our Fitting Room to help you find the best size and style, and marketing that showcases real women, everything we’ve built has centered on our customers.
Q: How did the Sarah Flint x ThirdLove collaboration come to fruition?
A: Sarah Flint and I are customers of each other’s brands and one day we were chatting about ThirdLove’s new sleepwear. Voila—the idea of collaborating was sparked.

Q: What do you love most about working with other female founders?
A: As an angel investor and advisor in many female-founded companies, I’m passionate about working with other women entrepreneurs. Partnering with another female-founded brand is a further extension of a commitment to lift each other up.
Q: The ThirdLove x Sarah Flint partnership is the first time you are working with a shoe brand. What excites you most about this new offering?
A: I love that Sarah Flint focuses on bringing comfort and style together, just like with all our products at ThirdLove. Our collaboration features the first ThirdLove PJs to feature a print, blending one of Sarah’s beautiful florals onto ThirdLove’s lightweight woven PJs—a perfect pairing for summer!

Q: What is your favorite Sarah Flint shoe and why?
A: I don’t think it’s fair to make me choose just one. I love the Sacchetto Ballet Flat for everyday wear, and the Perfect Block Sandal 60 for dressing up.
Q: What is your morning or night routine?
A: My morning routine is wake up and do some quick email triage, then get the kids ready for school, do a quick Peloton workout, and then head to work.

Q: What is one thing that is always on your bedside table?
A: Eye mask & earplugs.
Q: What is one of your guilty pleasures?
A: Baked goods (preferably cookies and pies).

Q: Heels or flats?
A: Flats.
Q: Short PJ set or Pant PJ set?
A: Pant.