Road policing officers stopped a Peugeot 207 on the M80 near to Cambusbarron at about 11am on Sunday.
They found 2kg of heroin with an estimated street value of £50,000.
Police said that a 30-year-old man and a 26-year-old woman were arrested and charged in connection with alleged drug, road traffic and other offences.
They are expected to appear at Stirling Sheriff Court on Monday.