Ask The Scientists was created to help individuals understand and master the science behind USANA’s top-quality products. The company’s focus has always been creating high-quality nutritional products that are built on one simple idea: if you feed the cells in your body exactly what they need, your health will benefit. This concept has continued to fuel USANA’s endless drive to innovate and advance the science of cellular nutrition—putting a healthy, happy life within reach for all.

Along with developing some of the best health supplement products in the world, USANA is also educating the public about the human body, health, and how the company’s products impact the body. You can find that information here on You can read about everything from quick answers to some of your questions on USANA products, to tips on how you can take control of your health.

USANA’s Research and Development and Ask the Scientists Team Members

Rob Sinnott, PhD

Chief Scientific Officer

Rolando L. Maddela, MPH, MD, CCRP

Executive Director of Global Health Education and Nutrition Research

Dr. Brewer joined USANA in 2016 as a senior scientist, with a background in molecular biology and nutrition. She completed her bachelor’s degree in biological sciences at the University of Alaska Anchorage and her PhD at the University of Alabama at Birmingham. Her dissertation work investigated impacts of diet and nutrition on aging and longevity. Dr. Brewer’s interest in improving health through science led her to USANA. Since joining USANA, she has focused on all stages of product development, particularly products centered on the human microbiome—including research, design, and evaluation. She led the launch of the USANA Oral Probiotic, gives trainings and presentations internally and externally to associates, and guides new product development.

Rachel Brewer, PhD

Executive Director of Research and Development

Russ Barton, MS, CNS, CISSN

Senior Nutrition Scientist

Austin Winegar

Director of Health and Science Education Development

Kenny Tan

Director of Health and Science Education

Jeremy Tian, PhD, MD

Director of New Product Research

Keijun Koh

Director of Product Development

Mark Levy, PhD

Director of Product Validation

Katie Burton

Director of Product Development

Chuck Walton

Lead Development Scientist