ICH E6 Good clinical practice - Scientific guideline

The ICH Guideline for Good Clinical Practice (GCP) establishes an international standard for the design, conduct, recording, and reporting of clinical trials involving human participants. It outlines the responsibilities of sponsors, investigators, and other stakeholders to protect the rights, safety, and well-being of trial participants, while ensuring the integrity and credibility of clinical trial data.

The guideline provides a unified framework to facilitate the mutual acceptance of clinical trial results by regulatory authorities across ICH member regions, supporting global collaboration in drug development and ensuring consistent regulatory standards.

ICH E6(R3) introduces innovative provisions designed to apply across various types and settings of clinical trials, ensuring continued relevance in the face of ongoing technological and methodological advancements. This guideline provides a new language to facilitate innovations in clinical trial design, technology, and operational approaches. It encourages a risk-based and proportionate approach to conducting clinical trials, promoting fit-for-purpose solutions. It fosters transparency through clinical trial registration and result reporting and offers additional guidance to enhance the informed consent process.​

To provide clarity and better readability ICH E6(R3) has a new structure and is composed of:​

• An overarching principles and objectives document; ​
• Annex 1 (interventional clinical trials);​
• Annex 2 (additional considerations for non-traditional interventional clinical trials). ​​

The principles are intended to support efficient approaches to trial design and conduct. They are interdependent and should be considered in their totality to assure ethical trial conduct and reliable results. ​

Annex 1, including its Appendices, is intended to provide information on how the principles can be appropriately applied to clinical trials. ​

This Annex has been developed alongside the principles and objectives document to ensure consistency and to offer stakeholders a comprehensive package that can serve as a replacement for ICH E6(R2).

Annex 2 covers designs such as pragmatic clinical trials and decentralized clinical trials, as well as those trials that incorporate real world data sources. The goal of Annex 2 is to offer GCP considerations for clinical trials with various design elements and data sources, ensuring that they are fit for their intended purpose.​

This Annex should be read in conjunction with the Principles and Annex 1.

A consolidated version of the principles, Annex 1 and Annex 2 has been published.

The overarching principles and Annex 1 adopted by ICH and CHMP came into effect on 23 July 2025.

Annex 2 reached Step 4 following ICH adoption on 3 June 2026 and CHMP adoption on 25 June 2026 and will come into effect on 15 January 2027.

ICH E6(R3) guideline builds on key concepts outlined in ICH E8(R1) Revision of General Considerations for Clinical Studies. This includes fostering a quality culture and proactively designing quality into clinical trials and drug development planning, identifying factors critical to trial quality, and engaging interested parties, as appropriate, using a proportionate risk-based approach. ​

Keywords: Good clinical practice (GCP), decentralised, real-world, pragmatic, investigator, sponsor, protocol, investigator's brochure, trial design, safety reporting, informed consent, statistics, ethics committee, clinical study/trial report, clinical trials, innovation, design, proportionality, ICH E6(R3)

ICH E6(R3) - Consolidated guideline

ICH E6(R3) Guideline for Good Clinical Practice - Step 5

Adopted Reference Number: EMA/CHMP/ICH/162879/2026 Legal effective date: 15/01/2027

ICH E6(R3) - Principles and Annex 1 - Current version - effective from 23 July 2025

ICH E6 (R3) Guideline for good clinical practice (GCP) - Step 5

Adopted Reference Number: EMA/CHMP/ICH/135/1995 Legal effective date: 23/07/2025

Overview of comments on ICH E6 (R3) guideline

Reference Number: EMA/553381/2023 Rev.1

Draft ICH E6 (R3) Guideline on good clinical practice (GCP) - Step 2b

Draft: consultation closed Consultation dates: 26/05/2023 to 26/09/2023 Reference Number: EMA/CHMP/ICH/135/1995

ICH E6(R3) - Annex 2 - effective from 15 January 2027

ICH E6(R3) guideline for good clinical practice - Annex 2 - Step 5

Adopted Reference Number: EMA/CHMP/ICH/495903/2024 Legal effective date: 15/01/2027

Draft ICH E6(R3) guideline for good clinical practice - Annex 2 - Step 2b

Draft: consultation closed Reference Number: EMA/CHMP/ICH/495903/2024

Overview of comments received on ICH E6(R3) guideline for good clinical practice – Annex 2 - Step 2b

Reference Number: EMA/132793/2025

ICH E6(R2)

ICH guideline for good clinical practice E6(R2) - Step 5 - Revision 2

Adopted Reference Number: EMA/CHMP/ICH/135/1995 Legal effective date: 01/01/1997

Draft ICH guideline E6 on good clinical practice - Revision 2

Draft Reference Number: EMA/CHMP/ICH/337843/2021

ICH E6(R1)

ICH guideline for good clinical practice E6(R2) 4 - Step 2b - Revision 1

Draft: consultation closed Consultation dates: 04/08/2015 to 03/02/2016 Reference Number: EMA/CHMP/ICH/135/1995

ICH E6 (R1) guideline for Good Clinical Practice - Revision 1

Adopted Reference Number: CPMP/ICH/135/95