Hi
I generally use
Chemist 4 U - for Piriton,
Hyperdrug - for Hibiscrub and various other things. I use
VetUK for Arden Grange (always the cheapest) and bird food, so I sometimes add meds too which saves on postage, even when the actual item cost is a little higher. These are my preferred options and I tend to compare prices between them for all human/dog meds.
I've also used
Medisave , and I think I used
Petmeds once - but I don't find them cheap enough to use regularly.
Online human chemists need you to complete an online declaration about the use of certain medicines (like Piriton). I just say it's for dog use as directed by the vet - I've never had any questions back :)
It's worth mentioning that Lloyds Chemist on the high st have a pet section too. If I need to buy Hibiscrub but don't need anything else (for combined postage) then Lloyds is pretty good value. They sell Frontline and DAP products too if I recall.