Blue Medicine is a Normal Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Blue Medicine is Unlimited.
YGOPRODeck lists Blue Medicine for these formats: GOAT, OCG GOAT, Duel Links, Edison, TCG, OCG, Master Duel.
A listed print of Blue Medicine appears in Tournament Pack: 1st Season (TP1-008) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Blue Medicine is about $0.99 on Amazon (prices change frequently).
