Shelley Costantini


Shanna Tellerman

Our Story

Who we are

In April 2014, Shelley & Shanna came together as a team to found S4 Skincare.  Our mission is to improve everyone’s skin by providing healthy, accessible and environmentally conscious products.  We each brought to the table something different, particular and diverse.  Shelley brings decades of expertise building an esthetics business and understanding the particulars of clients skincare preferences and desires.  Shanna brings her background in art, tech and startups. 

The S4 principles are at the forefront of our daily activities and our business. We pour over ingredients looking for quality, healthy, natural and effective formulas that are easy to use and make sense.   We strive to serve our community and have a commitment to giving back as we grow the business. We volunteer for animal causes, sit on panels and boards that promote women, and we donate a portion of our profits to support local and global causes.

At S4 Skincare, we thrive on customer input and feedback, and in turn offer education and transparency across everything we develop.  It is important to us that our clients feel good and know that they are making a difference by choosing S4 Skincare.

We believe that simply cleansing and nourishing your skin with the right products can help you look and feel refreshed, rejuvenated, bright-eyed, relaxed, and beautiful.  We hope you will feel these things from your very first splash.

Where WE ARE

The S4 Skincare HQ is perched in the heart of San Francisco, surrounded by beautiful people who are eco-conscious, health-focused, awe-inspiring and tech savvy. We utilize our unique position to research and test products quickly, simply and efficiently in this close-knit urban environment.

Our Name

The S in our name stands for Skincare, Shelley, Shanna and our 4 core principles; Smart, Simple, Safe and Successful.  Our love of the letter S never seems to end ... special, sunshine, smiling, sweetness, splendid...

Our Products & Brand

The S4 products got their start in the professional skincare studio Shelley founded and ran for the 11 years prior to founding S4 Skincare.  Shanna was a frequent client of Shelley's at her salon and became fascinated by the idea of bringing the beautiful products Shelley had developed to more people.  Together we developed the idea for S4 over many months of brainstorming, planning and many glasses of wine.  Our vision was to build our brand and products as an online first business designed for the modern busy professional searching for results without compromising on ingredients.  We are excited to see this vision come to life and hope you will feel the love and thought that has entered into every aspect of S4 Skincare.