"Spirulina is the perfect antiaging ingredient. The proteins, healthy fat, and antioxidants will help skin appear firmer and more even toned, and it slows down the aging process in general," Smith explained.
You can DIY your own skin-firming mask by combining two parts spirulina (you can buy it in powdered form on Amazon) and one part water to make a paste. "With a large fan brush, paint over the face and any other areas you feel need a boost," she said. Let it set for 20 minutes and then rinse off.
For a premade treatment, try Erno Laszlo Firmarine Eye Serum ($80), which utilizes spirulina as a star ingredient.