Your search for "effervescent tablet" revealed the following:

Sale price £87.29 Regular price £90.00 Sale
Sale price £97.48 Regular price £130.00 Sale
Sale price £86.68 Regular price £110.00 Sale
On Sale from £43.53 Regular price £70.00 Sale
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Sale price £89.99 Regular price £130.00 Sale
Sale price £48.99 Regular price £50.00 Sale
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Sale price £169.90 Regular price £200.00 Sale
Sale price £189.49 Regular price £200.00 Sale
Sale price £13.99 Regular price £30.00 Sale