When a gastroenterologist and a nutrition scientist agree that something is broken, they don't write a think piece.
They build something better.
Who we are
38TERA® was founded on a simple conviction: the supplement industry had drifted too far from the science. Every formula we make is the direct result of two people who refused to let that stand.
Dr. Will Bulsiewicz
MD MSCI · Gastroenterologist
Co-FounderTwo decades in clinical practice. One recurring observation: the industry wasn't keeping up with the science. Dr. B decided to change that — from the inside out.
Simon Hill
MSc Nutrition · Physiotherapist
Co-FounderSimon built his career on one question: why is so much health advice so wrong? The answer took him from physiotherapy to nutrition science — and to a platform millions trust to get it right.
why it matters
Credentials aren't decoration.
They're the standard.
Most supplement brands borrow scientific language. At 38TERA®, the science is the foundation — not a trend, not a marketing brief. Dr. B brings clinical gastroenterology and peer-reviewed research. Simon brings the rigour to translate it without compromise.
Together, they're accountable to the evidence because they helped produce it.
20+
Years in clinical gastroenterology practice — Dr. B has seen what works, and what the industry gets wrong
x3
New York Times bestselling author — Dr. B's books have reached millions worldwide
5,400+
Citations across 74 peer-reviewed publications — Dr. B's research has shaped how the medical community understands gut health
50M
Podcast listens on The Proof— Simon's platform for evidence-based health
"We didn't want to build a supplement brand. We wanted to build a science company that happens to make products people can actually trust."
Dr. Will Bulsiewicz, MD, MSCI
Co-founder and clinical voice behind the microbiome-first formulation philosophy.
Simon Hill, MSc
Co-founder and nutrition science communicator helping shape how the evidence is translated for daily life.
The Weekly Digest
Expert insights, microbiome science, and practical advice — no fads, no fear.
