This article explores the legal and institutional transformation of the Mexican pharmaceutical sector, focusing on the period following Mexico’s entrance into the General Agreement on Tariffs and Trade (GATT) in 1986. The shift from protectionist policies to economic liberalization reshaped the regulatory and competitive landscape of the industry. Key legislative reforms, including the 1991 Industrial Property Law, the 1984 General Health Law, and the 1993 Foreign Investment Law, aligned the sector with global trade standards, thus affecting intellectual property, foreign investment, and pharmaceutical production. This article also examines the impact of international agreements like TRIPS, NAFTA, and USMCA. These legal and trade reforms fostered opportunities for multinational corporations, but also created challenges for domestic firms, particularly regarding intellectual property and growing reliance on generic drugs. This research article evaluates how these changes have affected competitiveness in the sector, innovation, and access to medicine, shedding light on the evolving dynamics of Mexico’s pharmaceutical industry in a globalized context.