Nutpea Berries cannot be used directly and only have a use as an ingredient for Pokéblocks.
A Nutpea Berry cannot be stolen by Thief or Covet, or exchanged by Trick.
The player will not be permitted to enter the Pokémon Cable Club Trade Center if a Pokémon in their party is holding this Berry. A Pokémon holding this Berry cannot be traded to Pokémon Colosseum or Pokémon XD: Gale of Darkness, nor can it be stored in the Western versions of Pokémon Box Ruby & Sapphire.
Petalburg Gym (from Norman after scanning the Nutpea Berry e-Reader card; repeatable if the card is scanned again and the player has no e-Reader Berries in the Bag or PC when talking to him) Transformation from a different e-Reader Berry after scanning the Nutpea Berry e-Reader card