Are Firehouse Subs Au Jus Mushrooms High in Histamine?

Firehouse Subs Au Jus Mushrooms

High histamine

These au jus mushrooms are high in histamine, mainly from the Worcestershire sauce.

Food here is usually assembled to order from components that were prepped earlier in the day, so it tends to be fresher than a drive-through and less fresh than cooking at home. Histamine builds up as protein foods sit, so how long the chicken or beef has been in the warmer matters as much as what is in the bowl. Treat the rating above as a starting point.

Gluten Histamine Liberator

This is mushrooms cooked with a vegetarian Worcestershire sauce and garlic.

Worcestershire sauce — the vegetarian Worcestershire is high in histamine and is the main driver here. It carries the savory au jus flavor through the whole topping.
The mushrooms — the mushrooms themselves run moderate, so even without the sauce this would not be a fully low option, but the Worcestershire is what tips it high.

Plain sauteed vegetables without the Worcestershire would be a gentler pick.

This rating comes from Firehouse Subs' own published ingredient statement, read on August 11, 2026. Restaurant recipes vary by location and change over time, so always check the current listing: source 1, source 2. How we rate foods →

Firehouse Subs Au Jus Mushrooms and Firehouse Subs are trademarks of their respective owners. This page is an independent histamine reference and is not affiliated with, endorsed by, or sponsored by the brand.