Hi, I’m Preston.

I’m Preston Johnson, a licensed pharmacist in Washington and California. I like a good question, a clear explanation, and a supplement label that doesn’t require a magnifying glass.

That One Pharmacist is a place to understand the everyday side of GLP-1s: what to eat, what to ask your own care team, and how to make sense of all the advice out there. You don’t need to have it all figured out before you get here.

I read the labels and dig into the research so I can explain the options in plain English. You’ll find answers, a small selection of products I’ve chosen, and a look at what goes into my own morning shake.