Evidence review
How to Read a ClinicalTrials.gov Record
A registration is a filing, not a review. Fifteen fields, two real peptide records, and the specific places where a record quietly tells you it has stalled.
First, what a registration is not
It is not a review. A record is the sponsor's own structured account of its own trial, published on a public timeline — its presence says an application to study something was filed and posted, not that a reviewer outside the sponsor's organisation judged the design, the dose or the compound.
It is not an approval. A registered trial of a compound tells you an application was filed to study it, and nothing about its regulatory status.
It is not a result. A record can sit in the registry for a decade describing a trial that produced nothing anyone can read.
What it is: a structured, timestamped, publicly amendable declaration of intent, and a very good place to catch a claim that has drifted from its evidence.
The header block
Sponsor and class. Each record names a lead sponsor and tags it INDUSTRY, NIH, OTHER_GOV or OTHER, plus any collaborators. NCT02637284 lists PharmaCotherapia d.o.o. as lead sponsor with Hospital Ángeles Tijuana as collaborator1.
Overall status. The values that matter most are RECRUITING, ACTIVE_NOT_RECRUITING, COMPLETED, TERMINATED, WITHDRAWN and UNKNOWN.
UNKNOWN is the one to learn. It means the record was in an active state and has not been verified by its sponsor within the registry's expected window. It is the registry's way of saying this has not been touched in a long time.
Dates, and the word that changes everything
Dates carry their own tag — ACTUAL or ESTIMATED — and the tag is where the information is. Older records sometimes carry a bare date with no tag at all: NCT00267527's start date is recorded simply as December 2005, with no type3.
Start date. Actual means it began.
Primary completion date. When the last participant's last primary-outcome measurement is expected or was taken. This is the clock that matters for results reporting.
Completion date. Usually later, covering follow-up.
Last update posted. The staleness signal.
Put those together on NCT02637284: first posted 22 December 2015, last update posted 22 December 2015, estimated primary completion February 2016, estimated completion March 2016, status UNKNOWN1. The record has not been edited since the day it appeared. Whatever happened to that trial, the registry does not know either.
Design
Allocation — RANDOMIZED, NON_RANDOMIZED, or NA. NA usually means a single-group study.
Intervention model — PARALLEL, CROSSOVER, SINGLE_GROUP, FACTORIAL, SEQUENTIAL.
Masking — NONE through QUADRUPLE, with a list of who was masked and sometimes a free-text description of how. Whether that field is load-bearing depends on what the endpoint is.
Primary purpose — TREATMENT, PREVENTION, DIAGNOSTIC, BASIC_SCIENCE. Worth checking: NCT02637284's primary purpose is BASIC_SCIENCE, not TREATMENT1.
Enrolment, with its own ACTUAL or ESTIMATED tag. An enrolment that is still ESTIMATED years after the estimated completion date is a record that never closed the loop.
Arms — read the labels, not the types
Each arm carries a label and a type: EXPERIMENTAL, ACTIVE_COMPARATOR, PLACEBO_COMPARATOR, SHAM_COMPARATOR, NO_INTERVENTION.
The types are entered by the sponsor and are not always right. On NCT07437547, the two arms are labelled "Arm 1: Experimental - BPC 157" and "Arm 2: Placebo Comparator - Placebo", and both are typed EXPERIMENTAL2. The label is accurate and the type field is not. If you filter records by arm type rather than reading them, you will miscount trials like this one.
Outcome measures: the primary is the promise
The primary outcome measures, with their time frames, are the trial's commitment. Everything else is exploratory by comparison, and a number quoted from a secondary endpoint should be described as one.
NCT07437547 declares two primaries: time to return to unrestricted sport participation in days at 8 weeks, and change from baseline to day 14 in MRI-assessed hamstring injury volume in cubic centimetres, measured by blinded central radiology review2.
That second one is a well-specified endpoint — a physical measurement, read by people who do not know the assignment. The first is a decision made by someone. Both are declared, which is the point of declaring them.
Sites
The number of locations tells you about generalisability and about scale. NCT07437547 lists a single site, in Shenzhen, for an estimated 120 participants2. NCT02637284 lists a single site, in Tijuana, for an estimated 421.
A single-site trial is not invalid. It does mean the result is entangled with one team, one population and one standard of care.
Results are a separate flag
A record carries a has-results flag independent of its status. COMPLETED with no posted results is an extremely common combination, and it is its own subject — see registered but never reported.
Also note what a future date forecloses. NCT07437547 has an estimated primary completion of 14 February 2027 and an estimated study completion of 17 February 20282. No result from that trial can exist in August 2026, and any claim citing it is citing a plan.
Six things worth flagging on sight
Status UNKNOWN, or a last-update date years before the estimated completion date.
Enrolment still tagged ESTIMATED long after the trial should have closed.
A single site paired with a large target enrolment.
Masking NONE with a self-reported primary outcome.
A quoted result whose timepoint does not match any declared primary outcome.
A completion date in the future, cited as though it were a finding.
A worked pass, in one paragraph
NCT07437547: a randomised, double-blind, placebo-controlled phase 2 trial of BPC 157 for acute grade II hamstring strain confirmed by MRI, lead sponsor tagged INDUSTRY, first posted February 2026, status recruiting, estimated enrolment 120, quadruple masking with identical prefilled syringes prepared under a randomisation code, one site, primary completion estimated February 20272. That is a properly specified trial that has not produced anything yet, and reading it carefully is exactly how you avoid mistaking a well-written protocol for a result. Our BPC-157 page holds the rest of that compound's file.
Frequently asked questions
Does registration on ClinicalTrials.gov mean a trial was approved or reviewed?
No. A record is the sponsor's own structured account of its own trial. Its presence says an application to study something was filed and posted — not that a reviewer outside the sponsor's organisation judged the design or the compound — and it carries no regulatory status for the compound itself.
What does a status of UNKNOWN mean?
That the record was in an active state and has not been verified by its sponsor within the registry's expected window. NCT02637284, a phase 1 BPC-157 study, was first posted in December 2015, was last updated the same day, carried an estimated completion of March 2016, and shows status UNKNOWN with no posted results.
Can I trust the arm-type labels on a record?
Read the arm labels rather than relying on the type field. On NCT07437547 both arms are typed EXPERIMENTAL even though one is labelled as the placebo comparator. The types are entered by sponsors and are not always corrected.
How do I tell whether a registered trial has actually reported?
Check the has-results flag, which is independent of the status field. A trial can show COMPLETED and still have nothing posted, and a completion date in the future means no result can exist yet — NCT07437547 has an estimated primary completion of February 2027.
References
- U.S. National Library of Medicine (2015). NCT02637284 — PCO-02: Safety and Pharmacokinetics Trial. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT02637284
- U.S. National Library of Medicine (2026). NCT07437547 — BPC 157 for Acute Hamstring Muscle Strain Repair. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT07437547
- U.S. National Library of Medicine (2006). NCT00267527 — A Study to Evaluate CJC 1295 in HIV Patients With Visceral Obesity. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT00267527
Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.
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