She was taken to the Royal Victoria Infirmary at 03:16 GMT and is said to be in a critical but stable condition.
Northumbria Police investigating what the drugs were and where they were bought have closed the Happy Chippy on Waterloo Street.
Three men aged 17, 26 and 38, have been arrested on suspicion of drugs offences.
Detectives have asked anyone with information to contact Northumbria Police or Crimestoppers.
A Newcastle chip shop has been closed after a woman who took "legal high" tablets became seriously ill.