The serum you are talking about is actually called a secretpotion. You have to go to Cianwood City's pharmacy. Once you talk to the clerk, he'll give you the secretpotion to give to the Ampharos in the lighthouse.
You can only get the SecretPotion after you have talked to Jasmine in the Olivine Lighthouse. Then she will ask you to get Ampharos some Medicine. You go to Cianwood City and talk to the guy at the Pharmacy and he will give you SecretPotion for Ampharos.
The SecretPotion gets rid of the Psyduck on Route 210.
Talk to Jasmine in Olivine Lighthouse first, and make sure you say 'Yes' when he asks if it is an emergency.
After you have defeated leader wake in pastoria city, Cynthia will give you a secretpotion, go to the psyducks and they will go away
You need the SecretPotion, which you get from the pharmacy in Cianwood City. You have to talk to Jasmine in the Lighthouse first before you get the SecretPotion.
after beating chuck and getting the secretpotion to anpheros
there is not a secretpotion in Pokemon silver Daniel robertson
The secretpotion does not exist in SoulSilver, due to there being no use, therefore this question is void.
To get the secretpotion, you first have to have talked to Jasmine. She will then direct you to the Pharmacy in Cianwood. If the guy does not give it to you, then it means you have to beat Chuck first.
go 2 cianwood city's pharmacy.the man at the counter will give u a secretpotion after u have seen amphy(the sick ampharos in the lighthouse)
to the pysducks ;)
Get the SecretPotion from Cynthia
She will be north from Solaceon Town
You have to get the SecretPotion from Cynthia.
The serum you are talking about is actually called a secretpotion. You have to go to Cianwood City's pharmacy. Once you talk to the clerk, he'll give you the secretpotion to give to the Ampharos in the lighthouse.
cythenia gives it to you .Im not sure how she gives it to you.