Evidence memo / Tissue repair & recovery

Secretin

Also: ChiRhoStim · human secretin · secretin stimulation test

Secretin (ChiRhoStim) is a gut hormone, the very first hormone ever discovered, now used as an FDA-approved diagnostic agent. Given by injection, it stimulates the pancreas so doctors can test pancreatic function, help diagnose a rare gastrin-producing tumor (gastrinoma), or improve imaging and access during pancreatic procedures. The Watchlist boundary is that it is a diagnostic tool, not a treatment, and that the popular 1990s claim it could treat autism was tested in trials and did not hold up.

Approved for specific usesApproved specific use

The verdict

Our read at a glance.

Whether secretin is understood as an approved diagnostic agent for pancreatic and gastrin testing, rather than a treatment, and whether the well-tested and negative autism claim is kept clearly in view.

The signal
As a diagnostic, secretin reliably stimulates the pancreas and is used to test pancreatic function, to help detect gastrin-producing tumors, and to aid pancreatic imaging and procedures. As a treatment for autism, by contrast, multiple randomized trials and systematic reviews found no benefit.
The unknown
Its diagnostic role is well defined; the main open questions are practical, such as how secretin-enhanced MRI imaging is best used, rather than any unproven therapeutic role.
Our read
A historic hormone with a clear, narrow modern job: it is an approved diagnostic that stimulates the pancreas for testing and imaging. It is not a treatment, and the once-hyped idea that it could help autism was carefully tested and failed, a clean example of a popular claim that the evidence did not support.

The mechanism

How it works.

Secretin is a hormone made by the lining of the upper small intestine. When acidic food arrives from the stomach, secretin is released and tells the pancreas to pour out a watery, bicarbonate-rich fluid that neutralizes the acid. Doctors use that same action as a test: giving secretin by vein makes the pancreas secrete on cue, so they can measure how well it works, collect fluid to look for a gastrin-producing tumor (which responds to secretin in a tell-tale way), or boost the flow and imaging during pancreatic procedures and scans. It is used to read the body, not to change it.

Safety & regulatory boundary

The consequential part.

Secretin is generally well tolerated as a single diagnostic dose, with occasional flushing or nausea and rare allergic reactions. It is approved only as a diagnostic agent, not a treatment, and it should not be used for autism, where controlled trials showed no benefit. ChiRhoStim (synthetic human secretin) is a prescription diagnostic given by a clinician.

What's next

What we're watching.

Refinements in secretin-enhanced pancreatic imaging and testing; no credible new therapeutic indication is on the horizon.

Context

Why this is discussed.

Secretin is a piece of medical history, the hormone whose discovery in 1902 created the whole idea of hormones. Today it is a diagnostic tool. It also became famous in the late 1990s when a small report suggested it might help autism, which set off enormous demand.

The evidence base

10 cited references.

Regulatory & labels1

DailyMed label: ChiRhoStim

ChiRhoClin, Inc. (FDA label) · 2025

Registered trials2

Imaging Biomarkers of Pancreatic Function and Disease

ClinicalTrials.gov · PHASE4 · ENROLLING_BY_INVITATION · 2023-01-18

Indexed literature (PubMed)7

Pancreas divisum

Varshney S et al. · Int J Pancreatol · 1999

Secretin-enhanced MR pancreatography

Matos C et al. · Semin Ultrasound CT MR · 1999

Advanced imaging of chronic pancreatitis

Choueiri NE et al. · Curr Gastroenterol Rep · 2010

Update on endoscopic pancreatic function testing

Stevens T et al. · World J Gastroenterol · 2011

Pancreatic function tests: when to choose, what to use

Boeck WG et al. · Curr Gastroenterol Rep · 2001

Keep reading

Related published memos.