Certification is required to bring in narcotic medication.
When bringing narcotic medication for own private use into EU/EES countries, you must be able to show a certificate that proves your right to take the medication with you. This applies regardless of whether you have the medication in your hand baggage or checked baggage. Narcotic medication includes many sleeping pills, tranquilizers and strong painkillers. Contact your chemist to get a so-called Schengen certificate issued.