Your search for "effervescent tablet" revealed the following:

On Sale from £34.40 Regular price £50.00 Sale
Sale price £81.50 Regular price £130.00 Sale
Sale price £33.37 Regular price £40.00 Sale
On Sale from £32.19 Regular price £40.00 Sale
On Sale from £29.44 Regular price £40.00 Sale
Sale price £16.99 Regular price £30.00 Sale
Sale price £51.99 Regular price £70.00 Sale
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Sale price £33.99 Regular price £40.00 Sale