Your search for "effervescent tablet" revealed the following:

Sale price £36.40 Regular price £40.00 Sale
Regular price £79.99
On Sale from £42.80 Regular price £60.00 Sale
Sale price £33.45 Regular price £40.00 Sale
On Sale from £22.99 Regular price £30.00 Sale
On Sale from £79.89 Regular price £95.00 Sale
Sale price £42.99 Regular price £50.00 Sale
Sale price £53.99 Regular price £70.00 Sale
On Sale from £39.95 Regular price £50.00 Sale
Regular price £44.29