Global Asthma Network (GAN) Phase I is the first study to provide individual-level data worldwide on asthma medicine use, management plan availability, and disease control in childhood, adolescence, and adulthood. This global report provides a novel insight on the use of medications by individuals with diagnosed asthma, how medicines are used relative to the severity of asthma symptoms, the use of asthma management plans, and factors related to asthma control across the life course in countries with different income economies. Data from 101777 children, 157784 adolescents and 193912 adults from 63 centers in 25 countries have revealed inhaled short-acting β2 agonist (SABA) and inhaled corticoids as the most used medicines, with a significant increasing use as the severity of symptoms increased for all age groups. However, an important proportion of individuals with severe asthma symptoms (44-60%) does not take inhaled corticoids, and this proportion is significantly higher in low country income categories. Contrary to current guidelines, oral SABA and theophylline are used across all age groups and country income categories. Management plans are used by 44-63% of asthmatics worldwide, which increases the probability of using inhaled and oral medicines. Asthma is better controlled in adults in comparison with children and adolescents, and a notable increased trend of poorly controlled asthma in all age groups is observed in less affluent countries. Improving compliance to recommended asthma medicine use and assuring the availability and affordability of quality-assured essential medicines across the life course are urgent needs to mitigate asthma burden, particularly in children and in less affluent settings.