We’re here to help pets live longer, healthier lives — with formulas backed by real research, not fads.
History worth repeating
From human health to pet wellness
PETNUTRA was founded by Rob Brewster to raise the standard of care for the animals we love. As the third generation behind Brewster Nutrition and Ingredients by Nature, Rob grew up immersed in science — watching his family pioneer citrus bioflavonoids, probiotics, and other innovations now used in leading human supplements.
Inspired by the lifelong companionship of his own pets, Rob saw an opportunity to bring that same evidence-based approach to animal wellness. PETNUTRA was born from a simple belief: our pets deserve the same care, precision, and purpose we expect for ourselves.
“For decades, we helped people feel their best through better nutrition. Now we’re doing the same for pets — and that feels even more personal.” — Rob Brewster, Founder
The breakthrough no one saw coming — citrus
When researchers at Ingredients by Nature developed ERIOMIN® — a patented citrus bioflavonoid clinically shown to support GLP-1 and microbiome health — it marked a breakthrough in metabolic support.
With exclusive access to this ingredient, Rob saw an opportunity to bring those benefits to pets — using the same clinical standards trusted in human wellness.
ERIOMIN® changed how we approach metabolic health in humans. Now, it’s redefining what’s possible in animal wellness.
Science first, love always
Tested for pets. Trusted by science.
At PETNUTRA, we don’t formulate based on trends. We develop with intention — partnering with leading researchers, veterinarians, and institutions like UC Davis to ensure every ingredient is optimized for pets.
From sourcing to delivery, we apply the same scientific rigor you’d expect in human wellness — because when it comes to the animals we love, there’s no such thing as "good enough."
Our past — and our future
Rooted in science
1932
Rob’s grandfather, Marshall Brewster, helps found Test Laboratories, focused on citrus, tomato, and alfalfa research.
The ABCs of nutrition
the 50's
Marshall Brewster, Rob’s grandfather, takes full ownership and renames it Brewster Nutrition. He becomes one of the first to work with citrus bioflavonoids — and travels the country teaching the “ABCs of Nutrition” in living rooms and community halls. His early supplement company was one of the first MLMs in the U.S.
Science-first innovation
1972
Rob’s father, Gregory Brewster, shifts the focus back to raw ingredients and introduces freeze-dried probiotics — while continuing to develop custom citrus bioflavonoid complexes.
Scaling with science
1997
Brewster Nutrition partners with Syntech International to advance extraction methods and research around metabolic health.
A new generations steps in
2008
Rob co-founds Ingredients by Nature, building on family legacy with a renewed focus on clinically backed, plant-based ingredients.
ERIOMIN® Earns U.S. Patent
2019
The company’s flagship citrus bioflavonoid complex is patented for its role in glucose metabolism and GLP-1 activation. (U.S. Patent No. 10,285,954)
Going global
2020
Human clinical trials expand and international patents are filed, establishing ERIOMIN® in functional health markets around the world.
PETNUTRA is born
2022
Rob launches PETNUTRA — combining 90+ years of citrus science with cutting-edge pet wellness. G-Loop™ becomes the first natural GLP-1 support system for pets, powered by ERIOMIN®.
Next-gen research, in motion
2024 and beyond
PETNUTRA partners with leading veterinary researchers to validate the future of natural GLP-1 support in companion animals.
From our (fur) family to yours
Every PETNUTRA formula reflects our belief that science-backed nutrition should extend to the pets we love. With transparency, clinical validation, and a whole lot of heart, we’re here to help pets live longer, healthier, happier lives.