Is Firehouse Subs Swiss Cheese High in Histamine?

Firehouse Subs Swiss Cheese

High histamine

Swiss cheese is high in histamine because it is an aged cheese.

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.

Dairy

It is a simple cheese of pasteurized milk, cultures, salt, and enzymes.

Swiss cheese — the aging process is what drives it up; as the cheese matures, histamine builds, which is why hard and aged cheeses run high.
Fresh dairy would differ — the milk it starts from is low, but once it is cultured and aged into Swiss, the level climbs, so there is no way around it in the finished cheese.

Asking for your sub without any cheese, or requesting a fresh mozzarella if offered, is the gentler path.

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 Swiss Cheese 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.