21 CFR Part 50 (Protection of Human Subjects)

21 CFR Part 50 is the Food and Drug Administration’s own regulation governing the protection of human subjects in clinical investigations of FDA-regulated products. It is a distinct legal track from the Department of Health and Human Services’ Common Rule (45 CFR 46), and research administrators, sponsors, and investigators working on trials involving drugs, biologics, or medical devices need to know when each applies — and when both apply at once.

What triggers Part 50: FDA jurisdiction, not federal funding

Under 21 CFR 50.1, Part 50 applies to clinical investigations regulated by FDA — most commonly, investigations conducted under an Investigational New Drug (IND) application (21 CFR Part 312) or an Investigational Device Exemption (IDE) application (21 CFR Part 812), or investigations that support or are intended to support an application FDA will review (e.g. a New Drug Application, Biologics License Application, or premarket approval). This is a fundamentally different trigger than the Common Rule’s: 45 CFR 46 attaches because a federal agency funds or conducts the research (or because an institution has voluntarily extended Common Rule protections to all of its human subjects research via its Federalwide Assurance). Part 50 attaches because the product falls under FDA’s statutory authority — it applies whether the study is funded by a federal grant, industry, or an institution’s own resources.

This means a purely industry-sponsored drug trial with no federal grant dollars anywhere in it is still squarely subject to 21 CFR Part 50, even though 45 CFR 46 would never apply to it on funding grounds alone. See FDA (Food and Drug Administration) for the broader regulatory-jurisdiction picture across INDs and IDEs.

Subpart B: informed consent requirements

The core of Part 50 for day-to-day trial administration is Subpart B, Informed Consent of Human Subjects (21 CFR 50.20-50.27):

• 50.20 — General requirements. No investigator may involve a human subject in FDA-regulated research unless legally effective informed consent has first been obtained from the subject or their legally authorized representative. The consent process must minimize the possibility of coercion or undue influence, and the information given must be in language understandable to the subject. Critically, 50.20 bars any consent language that has the subject waive, or appear to waive, the sponsor’s or investigator’s legal liability for negligence — so-called exculpatory language is prohibited from an FDA-regulated consent form.
• 50.23 and 50.24 — Exceptions from informed consent. Narrow, tightly conditioned exceptions exist for certain life-threatening emergency-research circumstances where obtaining prospective consent is not feasible, subject to specific safeguards (independent physician certification, IRB concurrence, and for 50.24, community consultation and public disclosure requirements for emergency-research exception studies).
• 50.25 — Basic elements of informed consent. Sets out what the consent document/process must disclose: the study’s purpose and procedures, foreseeable risks and discomforts, expected benefits (if any), alternative treatments, confidentiality of records, compensation and treatment available if injury occurs, whom to contact for questions, and the voluntary nature of participation with the right to withdraw at any time without penalty. This runs closely parallel to — but is a separately codified requirement from — the Common Rule’s own basic-elements list at 45 CFR 46.116.
• 50.27 — Documentation. Requires informed consent to be documented, ordinarily by a written consent form signed by the subject (or representative), with narrow IRB-approved exceptions for short-form or waived-documentation consent in specific circumstances.

See Informed Consent in Research: What It Requires and How It Works for the operational mechanics of building a compliant consent process across both regulatory tracks, and FDA Form 1572 for how an investigator formally commits to complying with Part 50 and Part 56 on an IND-regulated trial.

Subpart D: additional safeguards for children

Where a clinical investigation under FDA jurisdiction enrolls children, Subpart D (21 CFR 50.50-50.56) layers on additional protections beyond Subpart B — categorizing pediatric research by risk level and requiring escalating conditions (IRB findings on risk/benefit, and in the highest-risk category, a formal FDA/HHS-level review pathway) before children may be enrolled, along with a separate requirement for the child’s own assent in addition to parental/guardian permission where the child is capable of it. This structure closely mirrors, and was historically harmonized with, the Common Rule’s own Subpart D for children (part of the additional-protections subparts at 45 CFR 46 Subparts B-D).

Part 50 vs. the Common Rule: dual-track applicability

The Common Rule (45 CFR 46) and 21 CFR Part 50 are separate federal regulations, issued by different agencies (HHS/OHRP and FDA respectively), with different triggers, and they do not automatically defer to one another. In practice, three scenarios come up repeatedly in research administration:

• Common Rule only — federally funded (or institutionally covered) research that does not involve an FDA-regulated drug, biologic, or device. Governed by 45 CFR 46 alone.
• Part 50/56 only — an FDA-regulated clinical investigation (e.g. an industry-sponsored drug trial) with no federal funding and no Common Rule-covered institution involved. Governed by 21 CFR Parts 50 and 56 alone.
• Both apply — a federally funded (or Common Rule-covered institution’s) trial of an FDA-regulated product, such as an NIH-funded IND study. Here the study must satisfy both regulatory tracks concurrently: the IRB must apply both sets of criteria, and the consent document and process must independently meet both 45 CFR 46.116’s and 21 CFR 50.25’s elements. Where the two diverge even slightly, institutions generally build a single consent process and IRB review that satisfies the more stringent of the two requirements, rather than running parallel reviews.

FDA’s parallel IRB-oversight regulation, 21 CFR Part 56, works alongside Part 50 the same way 45 CFR 46’s IRB-review provisions work alongside the Common Rule’s consent requirements — Part 50 sets what consent must contain, Part 56 sets how the IRB must review and oversee it. See OHRP (Office for Human Research Protections) for the HHS-side oversight body and Common Rule (45 CFR 46) for the funding-triggered track this regulation runs alongside.