Betaine HCL

Betaine hydrochloride is betaine bound to hydrochloric acid, which dissociates in the stomach to lower gastric pH. It is worth separating from plain betaine, also called trimethylglycine, which is a methyl donor used for homocysteine lowering and athletic performance and does nothing for stomach acid.

The underlying condition is real. Hypochlorhydria — insufficient gastric acid — impairs pepsin activation and therefore protein digestion, reduces absorption of non-haem iron, vitamin B12, calcium, magnesium and zinc, and weakens the acid barrier against ingested pathogens and small intestinal bacterial overgrowth. Its prevalence rises with age, atrophic gastritis, chronic H. pylori infection, autoimmune gastritis, and prolonged proton pump inhibitor therapy. A pharmacokinetic study did demonstrate that betaine HCL temporarily re-acidifies the stomach in people on PPI therapy, restoring absorption of pH-dependent drugs — the single best piece of objective evidence the supplement has.

What does not exist is trial evidence that taking it improves digestive symptoms, nutrient status or any clinical outcome. The popular self-titration protocol — increasing capsules with each meal until a warm sensation appears, then dropping back one — is folk practice with no validation, and it conflates a burning feeling with a meaningful endpoint.

The safety issue is serious and often understated. Adding acid to a stomach with an existing ulcer, erosive gastritis or GERD can worsen mucosal damage, and the symptoms of low and high acid overlap heavily, so self-diagnosis is unreliable. Anyone with reflux, ulcer history or NSAID use should not take it, and a proper workup — H. pylori testing, and gastric pH assessment where available — should come before supplementation.