you can find a super potion in the golden rod department.
to get the secret potion(medicine)you need to go to cianwood
Secret Potion
Action Replay or Gameshark? You can look it up on SuperCheats.com
Yes there is. /////////////////////// What is it then?
secret potion which you get by surfing to cianwood starting from the beach in olivine
explore a bridge in kanto
yo need to get the secret potion from cianwood city and give it to ampharos
if I remember right its in a house in Olivine City
Fishing in Vermillion with a Super Rod.
If you have the super rod you can find them by the water at route 34.
Mostly safari zone
if its on pokemon soul silver, just use your super rod in violet city.