Research
The words a drug trial uses, and who they point at
Sponsor, investigator, subject, study. In marketing these words are loose. In the federal rules on investigational drugs each one is defined, and each definition attaches a different set of obligations to a different person.
A short section that decides who is on the hook
Federal drug trial rules open with a list of definitions. It reads like housekeeping and it is not.
Every later obligation in the part is written against one of these words. Change which word describes you and the duty list changes with it.
That matters here because the same words appear constantly in peptide marketing, where nothing forces them to mean anything in particular. Knowing the regulated meanings gives a reader a fixed edge to measure a claim against.
Clinical investigation, and the line through medical practice
A clinical investigation means any experiment in which a drug is administered or dispensed to, or used involving, one or more human subjects.
The rule then defines the word inside its own definition. For purposes of the part, an experiment is any use of a drug, except for the use of a marketed drug in the course of medical practice.
That exception is the whole boundary. A licensed prescriber using an approved medicine in practice is not running a study, however novel the use.
The exception turns on the drug being marketed. It does not stretch to a compound that has no approved product behind it, and it is not a general permission to experiment as long as a clinician is involved.
Sponsor
A sponsor means a person who takes responsibility for and initiates a clinical investigation.
The rule is deliberately broad about who that can be. The sponsor may be an individual or pharmaceutical company, governmental agency, academic institution, private organization, or other organization.
The role is defined by two acts, not by size or type: taking responsibility, and starting the thing.
A sponsor also does not normally run the study. The sponsor does not actually conduct the investigation unless the sponsor is a sponsor-investigator.
One sentence closes the obvious workaround. An organization that uses its own employees to conduct an investigation it started is a sponsor, not a sponsor-investigator, and those employees are the investigators.
Investigator, and subinvestigator
An investigator means an individual who actually conducts a clinical investigation. The test is immediate direction: the person under whose direction the drug is administered or dispensed to a subject.
The word individual is doing work. An investigator is a human being, never a company.
Teams are handled explicitly. Where an investigation is conducted by a team of individuals, the investigator is the responsible leader of the team.
Everyone else on that team has a name too. Subinvestigator includes any other individual member of that team.
Sponsor-investigator, the person who is both
This is the definition most likely to describe a clinic that says it runs its own research.
A sponsor-investigator means an individual who both initiates and conducts an investigation, and under whose immediate direction the investigational drug is administered or dispensed.
It is a person, not an entity. The term does not include any person other than an individual.
And the duties stack rather than merge. The requirements applicable to a sponsor-investigator include both those applicable to an investigator and a sponsor.
So a physician who designs a study, starts it, and administers the drug personally carries two full sets of obligations at once, not an averaged version of them.
Contract research organization
Work can be handed to an outside firm, and the rules name that firm.
A contract research organization means a person that assumes, as an independent contractor with the sponsor, one or more of the obligations of a sponsor.
The definition lists what those obligations look like in practice: design of a protocol, selection or monitoring of investigations, evaluation of reports, and preparation of materials to be submitted to the Food and Drug Administration.
Notice what is being transferred. Not tasks, obligations. A separate section of the part governs how that transfer has to be written down.
Subject
A subject means a human who participates in an investigation, either as a recipient of the investigational new drug or as a control.
The definition covers both arms of a study, which is why a person in a placebo group has the same status and the same protections.
Health is not part of the definition either. A subject may be a healthy human or a patient with a disease.
This is worth holding onto when a product page describes early study participants. Healthy volunteers in a first-phase study are subjects, and they are not the population the page is selling to.
Investigational new drug, and the application named after it
An investigational new drug means a new drug or biological drug that is used in a clinical investigation. The term also covers a biological product used in vitro for diagnostic purposes.
The rule flattens a distinction people often try to draw. Investigational drug and investigational new drug are deemed synonymous for purposes of the part.
The three letters used everywhere in this area are the application, not the substance. IND means an investigational new drug application.
It carries an older name as well. The rule states that IND is synonymous with Notice of Claimed Investigational Exemption for a New Drug.
That older phrasing describes the mechanism accurately. What is being claimed is an exemption from the ordinary prohibition on shipping an unapproved new drug.
The review body, under a broader name
An independent ethics committee means a review panel responsible for ensuring the protection of the rights, safety, and well-being of human subjects involved in a clinical investigation. It must also be adequately constituted to provide assurance of that protection.
The familiar American term sits inside that category. An institutional review board, defined and governed by the separate part on such boards, is one type of independent ethics committee.
The broader wording exists because studies happen in other countries under other names. The function is what the definition fixes, not the label on the door.
Two more that keep citations honest
A marketing application means an application for a new drug submitted under section 505(b) of the act, or a biologics license application for a biological product submitted under the Public Health Service Act.
That is the filing that seeks permission to sell. It is a different document from the investigational application, and the two are frequently blurred in promotional writing.
The act means the Federal Food, Drug, and Cosmetic Act. FDA means the Food and Drug Administration.
Both are worth stating plainly, because a page that cites the act without naming it is not giving a reader anything to check.
What to do with this vocabulary on a product page
When a seller describes research, ask which of these words applies to them. Did they initiate it, which would make them a sponsor, or did they buy a study someone else ran.
When a clinic says its physicians run studies, the sponsor-investigator definition is the one to hold up. It carries two duty sets, and those duties are documented.
When a page cites participants, check whether the people described were subjects in an investigation or customers giving feedback. Only one of those has a regulatory meaning.
And when the word experiment appears, remember the carve-out. Ordinary practice with a marketed drug is not a study, and nothing about a compound without an approved product behind it fits that carve-out.
Key takeaways
- A clinical investigation is any experiment giving a drug to human subjects, and an experiment is any use of a drug except a marketed drug used in the course of medical practice.
- A sponsor is whoever takes responsibility for and initiates a study, and may be an individual, a company, an agency, an institution, or another organization.
- An investigator is always an individual, defined by whose immediate direction the drug is administered; other team members are subinvestigators.
- A sponsor-investigator both starts and runs a study, cannot be a company, and carries the investigator and sponsor requirements at the same time.
- A contract research organization assumes obligations of a sponsor as an independent contractor, not merely tasks.
- A subject includes people in a control arm and includes healthy volunteers as well as patients.
- IND names the application, not the drug, and its older synonym describes it as a claimed exemption.
Frequently asked questions
What counts as a clinical investigation?
Any experiment in which a drug is administered or dispensed to, or used involving, one or more human subjects. The rule defines experiment as any use of a drug, except for the use of a marketed drug in the course of medical practice. That exception is what separates a prescriber treating a patient with an approved medicine from a study.
Is a sponsor always a company?
No. A sponsor is a person who takes responsibility for and initiates a clinical investigation. The rule says that person may be an individual or pharmaceutical company, governmental agency, academic institution, private organization, or other organization. The role is defined by initiating the study and accepting responsibility for it, not by the size or type of the party.
What is a sponsor-investigator?
An individual who both initiates and conducts an investigation, and under whose immediate direction the investigational drug is administered or dispensed. It cannot be a company, because the term does not include any person other than an individual. The obligations stack: a sponsor-investigator carries both the investigator requirements and the sponsor requirements.
Does a company that uses its own staff to run a study become a sponsor-investigator?
No. The definition addresses this directly. An organization that uses one or more of its own employees to conduct an investigation it has initiated is a sponsor, not a sponsor-investigator, and the employees are investigators. The sponsor duties and the investigator duties still both exist, but they sit with different parties.
What does IND actually stand for?
An investigational new drug application. It is the paperwork, not the substance. The substance is the investigational new drug, meaning a new drug or biological drug used in a clinical investigation. The rule also records an older synonym for the application, Notice of Claimed Investigational Exemption for a New Drug, which describes what it does: claim an exemption.
Is a person in a placebo group a subject?
Yes. A subject means a human who participates in an investigation, either as a recipient of the investigational new drug or as a control. The definition also covers both healthy volunteers and patients with a disease. The protections in the surrounding rules do not depend on which arm someone is in, or on how well they were to begin with.
Sources
Each document below is named as it names itself, with the date printed on that document rather than the day it was read.
- 21 CFR 312.3 — Definitions and interpretations — Office of the Federal Register, Electronic Code of Federal Regulations, August 2026
- 21 CFR 312.52 — Transfer of obligations to a contract research organization — Office of the Federal Register, Electronic Code of Federal Regulations, August 2026