According to the UK FCO travel advice, ALL travellers to and through the UAE must now register any medications in advance. Note this applies to ALL medications, and to both Arriving and Transit passengers.
Entry requirements section (Medication) - updated information and advice following an announcement by the UAE Ministry of Health that all tourists and residents entering the UAE will be required to complete an electronic form to obtain online approval to carry medication for personal use, prior to entering the country; Health section - revised guidance on sources of health information before travel
This article is clearer about the new legislation than the UK FCO alert:
E-Approval Required Before Bringing Personal Medicines to UAE Dubai OFW
Note that to register you have to set up an account with the UAE Ministry of Health, which is probably not compliant with European data protection standards.