About PETNUTRA
Three generations of nutrition science, now for your dog
PETNUTRA brings more than 90 years of family nutrition science to the dogs we love.
What we believe
Caring for a dog is a promise we keep makingevery day.
We believe that promise includes the care we give on the good days, for the health we can't see.
Our why
The dogs we do this for
For every great day they give us, we want to give back.
Our founder
Rob Brewster grew up in the family business
PETNUTRA was founded by Rob Brewster, the third generation of his family to work in nutrition science. He grew up watching his grandfather and father pioneer citrus bioflavonoids and probiotics for people. In 2008 he co-founded Ingredients by Nature, where ERIOMIN® was developed and studied in human trials.
The dogs in his life made the next step clear: give them the same care. PETNUTRA holds the exclusive rights to bring ERIOMIN® outside human health, and G-Loop™ is its first product.
"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
Where it comes from
From the citrus grove to the dog bowl
One lab in Reseda, California has worked on the same family of molecules since 1932.
The raw material
The grove
It starts as citrus. The bioflavonoids sit most densely in the parts a juicer discards.
Reseda, CA · Est. 1932
The lab
The lab extracts and standardizes it into ERIOMIN®, roughly 70% eriocitrin, batch after batch.
Human clinical data
The trials
ERIOMIN® has a decade of randomized, placebo-controlled studies behind it, all in people.
Built for dogs
The formula
G-Loop™ pairs ERIOMIN® with a prebiotic, a probiotic, and a postbiotic, which help the gut put it to work.
One daily stick
The pack
Each day's serving comes in its own stick, so there's nothing to measure.
Over any meal
The bowl
You pour it over your dog's food once a day. From there, the work happens on the inside.
Since 1932
Our family's timeline
- 1932
Rooted in science
Rob's grandfather, Marshall Brewster, helps found Test Laboratories, focused on citrus, tomato, and alfalfa research.
- The 1950s
The ABCs of nutrition
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.
- 1972
Science-first innovation
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.
- 1997
Scaling with science
Brewster Nutrition partners with Syntech International to advance extraction methods and research around metabolic health.
- 2008
A new generation steps in
Rob co-founds Ingredients by Nature, building on family legacy with a renewed focus on clinically tested, plant-based ingredients.
- 2020
The first patent
ERIOMIN® earns its first U.S. patent, for blood glucose support (No. 10,596,185).
- 2020
Going global
Human clinical trials expand and international patents are filed, establishing ERIOMIN® in functional health markets around the world.
- 2021
Two more patents
Two more U.S. patents follow on the same day. One covers eriocitrin's use for increasing GLP-1 levels (No. 11,197,880), and one builds on the blood glucose patent (No. 11,197,879).
- 2022
PETNUTRA is born
Rob launches PETNUTRA to bring ERIOMIN® to dogs.
- 2026
The Inner Circle opens
The first Inner Circle families bring G-Loop™ home.
Meet the scientists behind G-Loop™ on How it works.
From our family to yours
Try G-Loop™ with your dog before it launches, in the Inner Circle.
Apply for the Inner CircleContact us
Pet Nutraceuticals, Inc.
424 Baker Ave, #8, Whitefish, MT 59937
support@petnutra.com
(833) 258-8738
Monday to Friday, 9 AM to 5 PM Mountain Time