What is THPE and why is it in our Firming Serum Stick? 🤔 THPE stands for Tetrahydroxypropyl ethylenediamine which is a key ingredient to help the skin cells tighten to increase firmness by +90%.* This powerhouse ingredients works alongside RoC Retinol and Antioxidants to visibly reduce the appearance of lines while smoothing and lifting the skin. This fast absorbing serum stick also has an easy-to-use application to target not only the face, but the neck, chest, and even backs of hands. 🙌 Drop a 💡 if you’ve used this innovative serum in your routine!