Blue Potion
From Zelda Wiki.org
The Blue Potion first appeared in A Link to the Past and is used to restore both Health and Magic. Just like Red Potion and Green Potion you need an empty bottle to carry it in. Since A Link to the Past it has also appeared in Ocarina of Time, Majora's Mask, and The Wind Waker.
In Majora's Mask
In Majora's Mask you can either purchase a bottle of Blue Potion from the Ikana Canyon Business Scrub for 100 rupees or you give a Magic Mushroom to Kotake at the Magic Hags' Potion Shop who will then use it to create Blue Potions and sell them to you for 60 rupees each. They cure the Curse status Blue Bubbles inflict.
In The Wind Waker
There are two ways to obtain the Blue Potion in The Wind Waker. The first is to collect 4 Boko Baba Seeds from killing Boko Babas and then giving them to Hollo who will mix a blue potion for you. The second way is to collect 15 Blue Chu Jellys from Blue ChuChus and trade them to Doc Bandam on Windfall Island. He will use them to make a Blue Potion and give you the first sample for free, and from then on will have it for sale at 60 rupees a bottle. In the whole game, the blue potion is considered the 'ultimate potion' because it can restore your magic power and your health.
In Twilight Princess
There are also two ways to obtain Blue Potion in Twilight Princess. The first way is to slay a Blue Chu, found rarely throughout Hyrule and several dungeons, especially the Lakebed Temple, and scoop up its remains into an empty bottle. The remains of a Blue Chu act similarly to the blue potion would, restoring all hearts. The second way is to simply buy the potion itself from the Goron's son in Kakariko Village or from Malo Mart in Hyrule Castle at a reduced price. In Twilight Princess however, the Blue Potion only restores hearts as the magic meter was left out on this one.
