Authorities in both Thailand and Cambodia may require documentation that the medicine you bring into the country is for your own use, the Embassy of Denmark in Thailand writes as a reminder on their Facebook page.
As a traveler it is your responsibility to check, if you can bring medicine into the country you’re visiting. To do so, having the documentation needed is crucial – especially if you expect to bring large amounts of medicine, or if the medicine contains narcotic drugs.
The Danish Embassy therefore encourages Danes to check out the information on pill passports and medication certificates that they have right here.