Equitable access to essential medicines is crucial to improve population health and support economic growth. A diverse range of access strategies have been implemented to target barriers across the different dimensions of access. This thesis contributes to the evidence on access to medicines strategies, focusing largely on international coordination and policy. First, I conduct a scoping review to identify strategies instigated by different stakeholders to improve access across a broad range of therapeutic areas and country contexts (Chapter 2). The remainder of the thesis seeks to address some of the literature gaps identified in this review. I explore inequalities and inequities in WHO essential medicines compared with need (Chapter 3). I find that despite inequalities with listing concentrated in high burden disease areas (pro-high burden inequalities), inequities remain when assessing listing proportionally to need. I observe differences over time, across broad disease groups, and across country income levels. I highlight disease areas in which attention is required to either list or develop essential medicines. In Chapter 4, I examine the impact of voluntary licensing and patent pooling for hepatitis C on access to treatment. I find evidence that licensing increases treatment rate beyond what would be expected in its absence and find that the impact of licensing increases with time. This evidence supports the careful expansion of the Medicines Patent Pool to improve access in other therapeutic areas. Finally (Chapter 5), to explore the issue of rational use, I examine antibiotic consumption in reference to the WHO AWaRe (Access, Watch, Reserve) classification for optimising the use of antibiotics. Overall and per capita consumption varied across the eight high-income countries studied, but most countries were meeting the associated Access target. The results from this thesis can help inform appropriate access strategies to improve equitable access to essential medicines worldwide.