Officers have been informed that a quantity of medication was lost at some point over the weekend in the Longtown area.
A Cumbria Police spokesman said: “The medication, which is a month’s supply of Mirtazapine, has gone missing at some point since 4pm on Saturday 15th June.
“These drugs could cause harm if they are taken by people who do not medically require them.”
Police are urging anyone who may find medication, that does not belong to them, to take it to their nearest police station or pharmacy.