The Mahogany City gym leader is not in Cianwood. He is in the gym in Mahogany, not anywhere else.
It is on Cianwood City Island. You have to surf there from Olivine City. (NOTE: the gym in Olivine is actually the 6th Gym battle so go to Cianwood Gym first) Before you go to Cianwood City make sure you visit the Olivine lighthouse top floor to talk to the Olivine Gym Leader about a sick Pokemon first.
You have to go the top of the lighthouse in Olivine Town, and then you'll have to help her heal a sick Pokemon by going across the sea to a medic in Cianwood, and then bringing the medicine back to her. THEN she'll be waiting at her gym.
The 5th gym leader in Johto is Chuck. He is located in Cianwood City.
Go to the Cianwood Pharmacy by surfing to the West of Olivine. The man gives you the meds, fly or surf back to Olivine and head back up to the top of the tower.
You have to beat the gym leader, Pryce, in Mahogany City.
If you surf from Olivine City u will get to cianwood town. Chuck, gym leader of fighting type!
Go to mahogany town to beat pryce
listen to the the gym leader with the Pokemon dip wad Surf to Cianwood and visit the pharmacy there.
you get it at Cianwood city. Beat the leader (chuck) His wife outside will give you the HM.
you get hmfly in heartgold after beating chuck the 5th gym leader who uses fighting type in cianwood city..
It's in Cianwood. The 6th is in Ollivine, the 7th in Mahogony, and the last in Blackthorn. I know, the set up of the cities and the badges don't really match up, since you have to go through Ollivine to get to Cianwood. o__O You can beat Pryce in Mahogany Town before Chuck in Cianwood if you want, but it's usually harder that way.
The fifth gym leader is Pokemon HeartGold SoulSilver is Chuck. He is in Cianwood City, but in order to get there you need surf.
wich one blaine or pryce pryce is in mahogany town blaine is in the seafoam islands
Get the secretpotion from a guy there and go back to Olivine in the lighthouse and cure the Ampharos in lighthouse and then battle Jasmine
From mahogany city go up to the ice path and cross it.At the end is blackthorn city.
You will get itAfter you beated the Cianwood City Gym Leader ,A Girl will give you it right when you get out of the Gym .*Hope it Helped , Kruh .first beat the 5th johto gym leader in cianwood and there will be a old lady standing out side talk to her and she will give you the hm fly
goto olivine city and talk to jasmine in the lighthouse then to cianwood to get the mediciine