The Sweet Heart (Japanese: ハートスイーツHeart Sweets) is type of medicine introduced in Generation V. It is a heart-shaped chocolate that restores a Pokémon's HP.
When used from the Bag on a Pokémon, it heals the Pokémon by 20 HP.
Exchange
In Mistralton City, the player can give a woman ten Sweet Hearts in exchange for a Heart Scale. In Pokémon Black 2 and White 2, on Valentine's Day (February 14) and White Day (March 14), the woman will allow the exchange for only five Sweet Hearts.