The Essential Medicines List, or EML, published by the World Health Organization lists the medications considered to be most effective and safe to meet the most important needs in a health system.
It is frequently used by developed and developing countries to help develop their own local lists of essential medicines.
The list is divided into core items and complementary items. The core items are believed to be the most cost-effective options for key health problems and are usable with few additional health care resources. The complementary items (comprising about 25% of the total) either require additional infrastructure, such as specially trained health care providers or diagnostic equipment, or have a lower cost-benefit ratio.

The first list, published in 1977, contained 208 medications; the WHO updates the list every two years. The 22nd list, published in 2021, contains 479 medications. Most are available as generic products, but being under patent does not preclude inclusion.

A separate list for children up to 12 years of age, known as the WHO Model List of Essential Medicines for Children (EMLc), was created in 2007 and is in its eighth edition. It was created to help ensure that the needs of children were systematically considered, such as availability of proper formulations. This list is based on the 19th to 22nd editions of the main list.

See reference for more information.

Adapted from Wikipedia, the free encyclopedia. Internet. Available at https://en.wikipedia.org/wiki/WHO_Model_List_of_Essential_Medicines. Accessed on August 1, 2022.