Reported adverse effects
| Placebo | Zinc lozenge | |
| Total: | 42 | 46 |
| Any adverse effects at any visit | 13 (31%) | 29 (63%) |
| Stomach ache | 11 (26%) | 12 (26%) |
| Taste problems | 3 (7%) | 24 (52%) |
| Other adverse effects* | 1 (2%) | 11 (24%) |
| No adverse effects at any visit | 29 (69%) | 17 (37%) |
| No taste or ‘other’ adverse effects at any visit | 38 (90%) | 18 (39%) |
*Other adverse effects in the zinc group included: teeth and mouth felt dry or rough, aching in the mouth. Thus, many of them were overlapping with taste problems. The participant who withdrew from the trial on the first day is included in this table. For the comparison of any adverse effects at any visit, there is significant difference between the treatment groups with p=0.003 in the χ2 test.