first you have to go to a town and you then have to chase around the team galactic guy then he will give up from running from you and you can battle him then you will see this girl and she will give you the secret poshen you need.
There is no legitimate secret potion cheat for Pokémon Diamond, Pearl and Platinum version. One way to do this would be to use an Action Replay.
action replay ds
yea......there is three
The Psyduck are at the northern part of Route 210, standing in the way of the path. These are the Psyduck you will need to use the Secret Potion on.
by a bunch of revies and super potion and ethers also try to get all your Pokemon around level 60 and don't use graveler
There is no legitimate secret potion cheat for Pokémon Diamond, Pearl and Platinum version. One way to do this would be to use an Action Replay.
Pokemon league champion Cynthia will give it to you when you run into her at lake valor(near pastoria and sunyshore)
you get it l8ter in the game after u beat the water badge i think its the 6th badge
Ok, after you get the Secret Potion from Cynthia, proceed on Route 210. That should take you to the Cafe Cabin. Walk to the upper left corner, where the Psyduck are. Press "A" when it asks you if you want to use your secret potion. Note: even after you use the Secret Potion it will still remain in your Key Items section of the bag Hope it helped!!
Use a potion.
rt. 210 is above Solaceon Town. it is block by psyducks until you can cure their headaches with the secret potion
The Secret Potion is a Key Item which can not be discarded, sold or used until the required event with the troubled Psyducks.
you go down to the house next to the Pokemon center and inside is this guy, talk to him and he will give a secret potion.
Cynthia will give it to you.
Valor Lakefront
You get the secret potion by talking to the pharmacist in Cianwood City. His house is in the south, south east of the gym.
cianwood city