The ICH Guideline E6 (Good Clinical Practice, GCP) is an international ethical and scientific quality standard for planning, initiating, performing, recording, oversight, evaluation, analysis and reporting clinical trials involving human participants. It ensures the protection of participants’ rights, safety, and well-being while promoting the credibility and reliability of clinical trial data.
Developed by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), E6 harmonizes GCP principles across regulatory regions, including Argentina, Brazil, Canada, China, Chinese Taipei, Egypt, the EU, Japan, Jordan, the Republic of Korea, Mexico, Saudia Arabia, Singapore, Switzerland, Türkiye, the United Kingdom, and the U.S.A. It provides guidance on trial protocols, sponsor and investigator responsibilities, informed consent, and monitoring practices.
ICH E6 is a cornerstone for clinical research, emphasizing compliance with principles that have their origin in the Declaration of Helsinki. By fostering international consistency, it facilitates mutual acceptance of trial data by regulatory authorities, streamlining drug development and ensuring high standards of safety and integrity.
Since its initial publication in 1996, the guideline has evolved to address advances in clinical research, digital technologies, and proportionate, risk-based quality management.
- ICH E6(R1) – the original (1996): Established foundational, global GCP principles covering sponsors, investigators, IRBs/IECs, and essential documents, thereby focusing on participant safety, ethical conduct, and data integrity.
- ICH E6(R2) – first revision (2016): Introduced risk-based quality management, enhanced sponsor oversight, and put greater emphasis on computerized systems and electronic records to address key gaps as clinical trials had grown enormously in complexity, cost, and scale.
- ICH E6(R3) – full restructure (2025): Modernizes GCP for today’s clinical research landscape by encouraging risk-based and proportionate approaches to clinical trial conduct that accommodate a diverse, technology-enabled trial environment while keeping the core principles to protect the rights, safety and well-being of participants and assure the reliability of results.
- ICH E6(R3) Annex 2 (adopted 2026): Completes E6(R3) by specifically addressing decentralized, pragmatic, and real-world-data-based clinical trials, remote trial activities, and other innovative methods.
Find out more about the implications of Annex 2 for Sponsors.