Does that neutralize pepsin immediately as well?

Me no understandee.

Do you mean breakdown the acid in your stomach (stoppping reflex?).Pepsin breaks down proteins.

If you mean acid reflux- the most common reason for it (and very counter intuitive), is that your stomach is not acid enough. (Told you it was counter intuitive).

Acid reflux happens mostly when the sphincter muscle (same kind as yer arse) above your stomach is not activated by the acid weak concentrations. It stays open, allowing the acid to go into the esophagus - causing the burning sensation.

Raising the acid levels in your stomach makes the sphincter work - as it's supposed to work.

I can't remember the last time had 'indigestion'.

I keep my stomach 'acidy' with vinegar and lots of lemon/ lime in my foods.

ie Never eat big pharma antacids - (or milk/yogurt, to quieten the burn - they perpetuate the need to keep eating antacids.
A clever 'profit cycle', uh?

Sorry if I've got off topic - Just tryin' to help.....as for pepsin - what would be the reason for neutralizing this?
It's an enzyme that helps you digest stuff (proteins).