Condition deep-dive · 8 min read

GERD — what helps, what makes it worse

Updated 2026-05-02 · Reviewed by SupplementScore editors · No sponsorships

Gastro-oesophageal reflux is one of the conditions where supplement marketing diverges most sharply from supplement evidence. The marketing tells you to chase "low stomach acid" and supplement betaine HCl. The trial literature does not support that framing for the typical reflux patient. This guide separates the narrow set of supplements that actually help from the larger set that quietly makes reflux worse.

Read this first. Difficulty swallowing, food getting stuck, unintentional weight loss, vomiting blood or coffee-ground material, black tarry stools, anaemia of unknown cause, or new-onset reflux after age 50 needs prompt clinician assessment before any supplement experimentation. Long-standing reflux warrants endoscopic evaluation at some point because of the small but real Barrett oesophagus / oesophageal cancer risk.

Supplements that actually help reflux

Tier 1 evidence · Mechanical reflux barrier

Alginate-based products (Gaviscon Advance and equivalents)

10–20 mL (or 2 chewable tablets) after meals and at bedtime, as needed

Sodium or magnesium alginate forms a floating raft on top of stomach contents that physically blocks reflux during the post-meal window when most reflux occurs. Multiple RCTs show benefit comparable to acid suppressants for symptom relief in mild-to-moderate reflux. The OTC-supplement boundary is fuzzy here; alginates are widely available in pharmacies and health-food stores. Useful as primary therapy in mild cases or as add-on therapy when PPI alone is insufficient.

Tier 2 evidence · Mucosal coating

Deglycyrrhizinated licorice (DGL)

380–760 mg chewable tablets, 20 minutes before meals

Licorice extract with the glycyrrhizin removed (the compound that causes blood-pressure issues and pseudoaldosteronism). DGL appears to support oesophageal mucosal protection and has small trial signal for symptom relief in functional dyspepsia and reflux. Generally well tolerated. Important: ordinary licorice (whole, with glycyrrhizin) is not a substitute and carries blood-pressure and potassium risks.

Tier 3 evidence · Sleep-onset reflux specifically

Melatonin (low dose)

3 mg, 30 minutes before bed

Small trials suggest melatonin reduces nocturnal reflux symptoms, possibly via lower oesophageal sphincter tone effects independent of the sleep-onset effect. Effect size is modest. Reasonable as an add-on for users with primarily nocturnal symptoms. Generally well tolerated; morning sedation at higher doses is the main side effect.

Tier 3 evidence · Mucosal soothing

Slippery elm and marshmallow root

400–500 mg of either, with water, before meals

Mucilaginous botanicals that form a viscous coating on the oesophagus and stomach lining. Trial evidence is limited, but the mechanism is mechanical and the safety profile is essentially clean. Reasonable as a low-risk symptomatic adjunct. Take separately from medications by 1–2 hours — the same mucilage that coats the oesophagus can blunt drug absorption.

Supplements that quietly make reflux worse

This is the part of the article most people don't see in the marketing. Many supplements that are marketed for reflux either work mechanically against you or relax the lower oesophageal sphincter:

Peppermint oil (non-enteric-coated) — relaxes the lower oesophageal sphincter and reliably worsens reflux. Useful for IBS at lower-bowel level when enteric-coated; the wrong form here.
Spearmint (similar mechanism) — same problem as peppermint.
Chocolate (cocoa polyphenol concentrates at high dose) — methylxanthines relax the LES.
High-dose calcium carbonate — paradoxical acid rebound on stopping; useful as occasional antacid, problematic as daily routine.
Iron (oral) — direct mucosal irritation; well known to worsen GI tolerance, including reflux.
NSAIDs — not a supplement strictly speaking but worth flagging; direct mucosal toxicity and increased reflux risk.
Betaine HCl supplements — popular in the "low stomach acid causes reflux" framing. Increases gastric acidity, which can produce immediate worsening of reflux in patients who do have reflux. Not appropriate without clinician guidance.
Apple-cider vinegar (oral, undiluted or large quantities) — same problem as betaine HCl, plus dental enamel and oesophageal-irritation concerns.
Bromelain at high doses — mild proteolytic effect can cause GI upset.
Curcumin in oily emulsions taken on empty stomach — variable, but can worsen reflux in some users; with-food dosing is gentler.

The "low stomach acid causes reflux" framing — a careful look

The popular framing in alternative-medicine circles is that reflux happens because the stomach produces too little acid, the food sits too long, fermentation builds pressure, and the resulting reflux feels acidic because the acid that does exist is now in the wrong place. The clinical evidence does not support this framing as a general explanation for GERD. Hypochlorhydria does occur in specific populations (elderly, autoimmune gastritis, long-term PPI use) and matters there for nutrient absorption, but the typical reflux patient has normal-to-elevated acid output. Supplementing acid into someone with normal output is more likely to worsen symptoms than help.

That said, careful clinician-supervised trials of betaine HCl in patients with confirmed hypochlorhydria are reasonable; broad self-prescription is not.

The non-supplement layer that matters more

The interventions with the largest effect sizes in reflux are mostly behavioural: weight loss in overweight patients (consistently the largest single effect on symptom severity in trials), elevating the head of the bed by 10–15 cm for nocturnal symptoms, not eating within 3 hours of bedtime, and identifying personal trigger foods (which differ widely — coffee, alcohol, fatty meals, large meals, citrus, tomato, and chocolate are common triggers). Smoking cessation reduces reflux meaningfully. PPI therapy remains the most-effective pharmacological intervention for moderate-to-severe reflux when behavioural measures aren't enough.

Practical quick-start. For mild-to-moderate reflux: alginate (Gaviscon Advance equivalent) after meals and at bedtime + DGL 380 mg before meals + behavioural measures (weight management, head-of-bed elevation, no late meals). Reassess at 4 weeks. If symptoms persist, the next move is a clinician conversation about PPI therapy or H2-blockers, not stacking more supplements. Avoid betaine HCl, peppermint, and apple-cider vinegar self-prescription.