Good laboratory practices (GLPs) may not be legally required in full for supplement testing labs to follow in the U.S., but they are best practices that quality brands should demand of their contract lab partners. As Jen Johansen, vice president of quality, regulatory and government affairs, Cyanotech Corp., explains, GLPs are a set of principles and requirements for testing procedures, facilities, personnel, methods and references standards. GLPs are part of a larger quality system to ensure test results are reliable and consistent. While GLPs are not outlined in full in the dietary supplement regulations, sections of the mandated GMPs (good manufacturing practices) overlap with GLPs.