This was a randomized, controlled, four-way crossover study in 45 subjects with a tendency to suffer from moderate heartburn following some meals. The study was designed to assess the time to onset of the perceived soothing and cooling effects of the alginate raft-forming products, Gaviscon Liquid (peppermint), Gaviscon Double Action Liquid (peppermint) and Gaviscon Powder Formulation (fresh tropical), compared with a non-active sublingual control. All three Gaviscon products provided significantly faster soothing and cooling effects compared with the control. Based on the upper 95% confidence limits for the median, time to onset of soothing was perceived within 3.15 min, 3.08 min and 4.05 min for Gaviscon Liquid, Double Action Liquid and Powder Formulation, respectively. Similarly, time to onset of cooling was perceived within 1.95 min, 1.23 min and 11.22 min for Gaviscon Liquid, Double Action Liquid and Powder Formulation, respectively. The results show that Gaviscon Liquid and Gaviscon Double Action soothe within 3.15 min and cool within 1.95 min.