Apple cider vinegar is one of the most talked-about home remedies for reflux, and it's also one of the more contested, since the underlying theory contradicts a lot of standard reflux advice.
The theory behind it
Some proponents argue that reflux in certain people is caused by too little stomach acid rather than too much, and that a small amount of vinegar before meals can support digestion in that scenario. This idea (hypochlorhydria as a reflux cause) has some plausibility for a subset of people, but it isn't the dominant, well-established cause of reflux, which is more consistently linked to a weak LES and excess or poorly-controlled acid exposure to the esophagus.
Why it can backfire
For most people with typical reflux, adding an acidic substance directly to an already irritated esophagus is more likely to worsen symptoms than help, which is why apple cider vinegar produces such mixed and contradictory anecdotal reports — it may genuinely help a small subset of people while making things worse for the larger group.
If you want to test it cautiously
A very small amount (a teaspoon) heavily diluted in a full glass of water, tried once and monitored closely, is a more cautious approach than starting with a concentrated dose. If symptoms worsen at all, that's a clear signal to stop rather than push through.
