Substances are internationally controlled (IC) when they are included in one of the three United Nations Conventions of 1961, 1971, or 1988. A substance that is internationally controlled is automatically controlled at the national level in countries that are signatories to these conventions. In addition, countries may also place a substance not included in the Conventions under national control.
The Convention of 1961 (also called the Single Convention, or the Convention on Narcotic Drugs) includes opioids both natural and synthetic. The Convention of 1971 includes psychotropic substances. The scheduling of Conventions 1961 and 1971 take into account the medical and scientific use measured against their particular risks to public or individual health.
The Convention of 1988 includes precursor substances with little or no use in the medical and scientific field.

Balancing access and prevention
Although drug control regulations are needed, if they are overly restrictive, they can obstruct access to controlled medicines for therapeutic use. In the same manner, if regulations are too weak, diversion and nonmedical use can occur.
A balance must therefore be struck between medical and regulatory requirements.
To adequately address the need for medication and prevent potential harms, proper regulation of controlled medicines needs to be enforced.
In addition, it is imperative for health care professionals to have appropriate education, including how to perform a careful initial assessment of patients prior to prescribing, as well as educating the patient on proper use.

Adapted from United Nations - International Control of Medicines. Internet. Available at https://syntheticdrugs.unodc.org/syntheticdrugs/en/access/international-control-of-medicines.html. Accessed on August 3, 2022.