What Is GCP? Good Clinical Practice Explained Simply
Every clinical trial in the world, from a small academic study to a global Phase III program, runs under one international quality standard: ICH Good Clinical Practice, usually shortened to GCP. The Clarity Clinical Solutions video "What Is GCP? Good Clinical Practice Explained Simply" walks through what the standard says, where it came from, and who has to follow it. Here is the same ground, with the regulations behind it.
What GCP actually is
The formal name of the GCP guideline is ICH E6, and it is the international standard for designing, conducting, recording, and reporting clinical trials (ICH Efficacy Guidelines). It was written by the International Council for Harmonisation, the body that brings regulators from the US, the EU, and Japan to the same table (ICH history).
GCP has two core goals: protect the rights and safety of the people who join trials, and make sure the data those trials produce is credible. In the US and Europe the standard has the force of law. The FDA has built GCP principles into its own regulations for clinical trials (FDA regulations on good clinical practice), and the EMA does the same on its side.
Why GCP exists
GCP is a response to real failures. The video points to thalidomide, which caused severe birth defects in an estimated 10,000 babies and helped push through the Kefauver-Harris amendment requiring proof of efficacy and consent. The Tuskegee syphilis study and the Declaration of Helsinki built the ethical framework that followed. Then, in 1990, regulators and industry formed the ICH to harmonize rules that had grown apart (ICH history). Before that, a sponsor might run a trial one way in one country and another way somewhere else. GCP ended that chaos.
The 13 core principles
GCP rests on 13 principles, all of which the video lists:
- The trial must follow the Declaration of Helsinki.
- Benefits must outweigh risks.
- Subject rights and safety come first.
- Adequate information must support the trial.
- The trial must be scientifically sound.
- The trial must follow the approved protocol.
- Medical care of subjects is the investigator's responsibility.
- Staff must be qualified.
- Informed consent is required.
- Records and data must be handled properly.
- Confidentiality must be protected.
- Investigational products must meet GMP (good manufacturing practice).
- Quality systems must be in place.
None of these is optional. Together they are the reason regulators, doctors, and patients can trust a trial's results.
Who is responsible for what
The investigator runs the study at the site. Under GCP, the investigator must have documented qualifications and GCP training, take responsibility for all medical decisions about subjects, and personally supervise the trial. Delegating everything is not allowed. The investigator reviews adverse events, signs off on eCRF pages, and stays available for inspections. The investigator site file holds the essential documents that prove compliance.
The sponsor runs the whole program. Sponsors must put a quality management system in place, appoint qualified monitors to oversee sites, handle regulatory submissions and safety reporting, make sure the investigational product meets GMP, and maintain the trial master file. The monitor is the sponsor's eyes and ears at the site.
The institutional review board (IRB) protects subjects from the outside. It must review and approve the protocol, the consent form, and recruitment materials before the trial starts, then keep reviewing at least annually. It can suspend or terminate a trial at any time, and it has to document how each member voted.
Informed consent and protocol compliance
The consent form must include eight essential elements: purpose, procedures, risks, benefits, alternatives, confidentiality, compensation for injury, and voluntary participation. Consent must be obtained before any trial-related procedure, and the subject must have adequate time to think. In the US, these requirements are written into 21 CFR Part 50, the FDA's informed consent regulation (21 CFR Part 50). The signed form is a regulatory document filed in both the medical record and the investigator site file.
GCP also requires strict adherence to the approved protocol. Any departure is a protocol deviation. Minor ones, like a visit two days late, must be documented. Major ones, like enrolling an ineligible patient, must be reported to the IRB. Willful non-compliance can get an investigator disqualified by the FDA, which is a permanent bar from conducting research.
Safety reporting, records, and inspections
Adverse events are recorded in the eCRF and followed until resolution. Serious adverse events, ones that are life-threatening or lead to death or hospitalization, go to the sponsor within 24 hours. SUSARs, suspected unexpected serious adverse reactions, go to regulators within 7 to 15 days.
Records are a big deal. GCP defines the essential documents, and they live in the investigator site file and the trial master file. Records must be kept for at least two years after the last marketing application approval; in practice that means 15 to 25 years. When a site closes, records transfer to the sponsor or an archival facility. Abandoned records are a serious violation.
The FDA routinely inspects sites, sponsor offices, IRBs, and laboratories. Inspectors look at informed consent, protocol compliance, adverse event reporting, drug accountability, and the audit trail. Inspections run two to five days and end in one of three outcomes: no action indicated, voluntary action indicated, or official action indicated. The FDA conducts roughly 200 to 300 clinical investigator inspections a year.
The consequences of violations are severe. The FDA can reject all data from a site or an entire trial, which can waste millions of dollars and years of work. Investigators can be disqualified. Sponsors can face fines and criminal prosecution. The video notes one 2022 case where a major pharmaceutical company paid $4.5 billion. Beyond the legal side, violations erode public trust in research, and that damage is harder to price.
The bottom line
GCP, ICH E6, is the international standard for ethical clinical trials: 13 principles covering ethics, consent, data, and quality, with defined responsibilities for investigators, sponsors, and IRBs. Inspections enforce it, and the penalties are real. GCP exists because of past failures, and it is not a suggestion. It is the foundation that lets regulators, doctors, and patients believe that clinical trial results are true.
This article is based on the Clarity Clinical Solutions video "What Is GCP? Good Clinical Practice Explained Simply." Watch it here: What Is GCP? Good Clinical Practice Explained Simply
References
- Clarity Clinical Solutions — "What Is GCP? Good Clinical Practice Explained Simply" (source video). https://www.youtube.com/watch?v=CDb3YL1Z4tw
- ICH — Efficacy Guidelines index (ICH E6 Good Clinical Practice). https://www.ich.org/page/efficacy-guidelines
- ICH — History of the International Council for Harmonisation. https://www.ich.org/page/history
- FDA — Regulations: Good Clinical Practice and Clinical Trials. https://www.fda.gov/science-research/clinical-trials-and-human-subject-protection/regulations-good-clinical-practice-and-clinical-trials
- eCFR — 21 CFR Part 50, Protection of Human Subjects (informed consent requirements). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-50