Supplement analysis backed by scientific evidence · PT

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Moderate evidenceGut health

Sodium Alginate

A seaweed fibre that forms a floating gel raft on top of stomach contents. It gives real short-term heartburn relief, adds little on top of a PPI, and does nothing measurable for appetite.

Evidence last reviewed: August 2026

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What the science says

  • Symptomatic reflux relief Moderate evidence

    A meta-analysis of over-the-counter GERD therapies found alginate/antacid combinations gave up to a 60% relative benefit increase over placebo for symptom relief — the largest effect among the OTC options examined.

  • Pooled RCT results are less impressive Limited evidence

    A systematic review of 11 RCTs found individual trials favouring alginate but no statistically significant pooled difference versus placebo or antacids, and a separate meta-analysis of four RCTs found adding alginate to a PPI did not significantly improve heartburn scores.

  • No effect on appetite or satiety Limited evidence

    A randomized placebo-controlled trial in 48 overweight and obese adults found 10 days of sodium alginate had no effect on gastric emptying, satiation, calorie intake at a free-choice meal, or gut satiety hormones.

Dosage & safety

Studied doseFor reflux, 500–1,000 mg of sodium alginate (or 10–20 mL of a liquid raft formulation) after meals and at bedtime.
SafetyVery well tolerated. Liquid raft formulations can carry a substantial sodium load, which matters in heart failure and hypertension. As a viscous fibre it can slow absorption of other medicines — separate doses by about two hours.

Scientific references

Where to buy

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