Exhibit 99.1 Avantor® Reports First Quarter 2025 Results RADNOR, Pa. – April 25, 2025 – Avantor, Inc. (NYSE: AVTR), a leading global provider of mission-critical products and services to customers in the life sciences and advanced technology industries, today reported financial results for its first fiscal quarter ended March 31, 2025. "Our first-quarter results demonstrate disciplined execution and a continued focus on cost management in a dynamic macro environment," said Michael Stubblefield, President an ...