Health Literate

Health Literate

Field Notes #3: The Serotonin Stat That’s Only Half the Story

the gut produces most of your serotonin. here is why that does not mean what most people think it means.

Agy | Health Literate's avatar
Agy | Health Literate
Mar 31, 2026
∙ Paid

Hello again! Third installation of Field Notes is here. I appreciate your patience with me last week as I was swamped with coursework. I’m back and working to stay on schedule — which is why you’re hearing from me again in a short time span. Don’t worry, after this you’ll have the rest of the week off :)

In this issue:

  • Why “90% of your serotonin is made in the gut” is true but incomplete

  • What peripheral serotonin is actually doing

  • Where mood-relevant serotonin comes from instead

  • The tryptophan fork in the road most people have never heard of

  • Why the real gut-brain connection runs on entirely different pathways

  • What the upcoming psychobiotics series is going to unpack

Disclaimer: I do not cover herbs in this issue! This is a small appetizer, if you will, of my upcoming series which will cover herbs in detail.

Before we get into it, I want to take a moment to acknowledge two people who recently became founding members of The Buffalo Herbalist: Tracie and Susan.

Choosing to show up for someone’s work at that level is not something I take lightly, and I especially do not take lightly the fact that in this economy, it is a real act of generosity. That goes for every single paid subscriber reading this. Whether you joined recently or have been here for a while, your support is what makes it possible for me to keep going deeper, keep citing my sources, and keep doing this work the way it deserves to be done.

It means more than I can adequately say.

Thank you, genuinely.

a close-up of some leaves
Photo by ethan on Unsplash

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