The amount of unused medicines is estimated to be costing about £500,000 a year in Jersey, says the government.
It has asked islanders to manage orders more carefully to help manage medicine supplies, protect healthcare resources and minimise environmental impact.
It said such waste remained a “significant issue” and, in the UK, up to 10% of all medicine dispensed was wasted and about half of all medicines returned to pharmacies for disposal was unopened.
The government said a new awareness campaign about the issue was not aiming to restrict access to medicine, or for people to go without treatment, but was asking them to “only order the items they currently need”.