Magnesium connects to reflux in a couple of different ways, some more direct than others, which makes it worth understanding both sides.
Magnesium-containing antacids
Some common antacids contain magnesium hydroxide, which neutralizes acid directly and also has a mild laxative effect at higher doses — something to be aware of if using magnesium-based antacids regularly, since it can affect bowel habits.
PPIs and magnesium depletion
Long-term PPI use has been associated with lower magnesium levels in some people, since stomach acid plays a role in magnesium absorption. This is one of the nutrient considerations that comes up in discussions about extended PPI use, and it's part of why periodic bloodwork is sometimes recommended for people on long-term PPI therapy.
Magnesium as a general supplement
Separate from antacid use, general magnesium supplementation (for sleep, muscle function, or other reasons) doesn't have strong direct evidence for treating reflux on its own, though better sleep and reduced muscle tension from adequate magnesium levels could plausibly have small indirect benefits given how closely reflux, sleep, and stress are connected.
If you're on long-term PPI therapy, magnesium levels are a reasonable thing to ask your doctor about checking periodically rather than something to self-supplement without guidance.
