The NCA said it believes the Class A drug is being put into hard boiled sweets to avoid suspicion from door and security staff at entertainment venues.
It issued the warning after gaining intelligence during an ongoing criminal investigation, and following a seizure of almost half a litre of liquid LSD in the Manchester area – enough to make more than five thousand sweets.
In a statement on its Facebook page, NCA said the sweets were being marketed to the student community in particular.
“We are asking that staff at entertainment venues be vigilant and consider refusing entry to customers or groups of customers carrying small amounts of such sweets,” added the agency.