Quick facts
- Class
- Gastrointestinal peptide hormone
- Brand name
- ChiRhoStim (human secretin)
- Approved for
- Diagnostic pancreatic/gastrin testing
- Administration
- Intravenous (clinical)
- Status
- FDA-approved (diagnostic)
Key takeaways
- Secretin was the first hormone ever discovered, in 1902, and helped establish the entire concept of hormones.
- Its modern role is diagnostic: stimulating pancreatic secretion and aiding diagnosis of conditions such as gastrinoma.
- It is a clinician-administered prescription agent, not a supplement or self-administered therapy.
- Once heavily studied as an autism treatment, secretin was refuted by multiple randomized controlled trials showing no benefit.
- In the US it is approved and marketed as ChiRhoStim for specific diagnostic indications only.
Overview
Secretin holds a unique place in the history of physiology as the first hormone ever discovered. In 1902, British physiologists William Bayliss and Ernest Starling identified a substance released by the lining of the small intestine that stimulated the pancreas to secrete fluid. Their work introduced the very concept of a hormone: a chemical messenger carried in the bloodstream to act on a distant organ. The word hormone itself was coined shortly afterward to describe this category of signaling molecule.
Today secretin is a synthetic peptide used as a diagnostic agent rather than a treatment. In the United States it is marketed as ChiRhoStim and is administered by clinicians to provoke and measure the secretory response of the pancreas and certain other tissues. It is not a supplement or a wellness product.
Secretin is also widely known for a different reason: it was once studied intensively as a possible treatment for autism. That hypothesis was tested and ultimately refuted, making secretin a frequently cited example of how careful clinical research can correct an early, hopeful claim.
How it works
Secretin is a small peptide hormone normally produced by specialized cells in the duodenum, the first part of the small intestine. When acidic contents from the stomach enter the duodenum, these cells release secretin into the bloodstream. Its primary job is to signal the pancreas to release a watery, bicarbonate-rich fluid that neutralizes stomach acid and creates the right environment for digestive enzymes.
Secretin acts on receptors found on pancreatic duct cells and also influences bile flow from the liver and certain functions in the stomach. By binding these receptors, it triggers the secretion of fluid and bicarbonate, which can be collected and measured during a diagnostic procedure.
In clinical testing, giving synthetic secretin produces a predictable, measurable surge in pancreatic output. Clinicians use this controlled stimulation to assess how well the pancreas functions or to provoke abnormal hormone release in specific tumors, allowing the response to be sampled and analyzed.
Research & evidence
The established, evidence-based uses of secretin are diagnostic. It is used to stimulate pancreatic secretion so that the fluid can be collected and analyzed for pancreatic function testing, and to help diagnose gastrinoma, a hormone-secreting tumor. In gastrinoma testing, secretin paradoxically raises gastrin levels in affected patients, producing a distinctive pattern that aids diagnosis. It is also used to aid identification of certain pancreatic ducts during specialized endoscopic imaging.
Secretin is most famous in the research literature for the autism hypothesis. After anecdotal reports in the late 1990s suggested behavioral improvement in some children, the idea attracted enormous public attention. Numerous randomized controlled trials were subsequently conducted to test it rigorously.
Those trials consistently found no meaningful benefit of secretin for autism symptoms compared with placebo. The collective evidence is strong and consistent, and major reviews concluded secretin is not an effective treatment for autism. This episode is now used as a teaching example of the importance of controlled trials over anecdote.
Use & side effects
This encyclopedia does not provide dosing protocols. Secretin is a prescription diagnostic agent administered intravenously by trained healthcare professionals in a clinical setting, typically as part of a structured testing procedure with sampling and monitoring. It is not self-administered and is not used as an ongoing therapy.
Because it is given as a single controlled dose under supervision, secretin is generally well tolerated in diagnostic use. Reported effects can include transient flushing, nausea, abdominal discomfort, or sensations related to the procedure itself. As with any injected protein, allergic or hypersensitivity reactions are possible, which is one reason administration occurs in a monitored environment.
Any decisions about diagnostic testing with secretin, including suitability, preparation, and interpretation of results, are made by qualified clinicians. Individuals should never attempt to obtain or use such agents outside of professional medical care.
Legal status
Secretin is an approved prescription product in the United States, where the synthetic human form is marketed as ChiRhoStim for diagnostic use. Its approved indications relate to stimulating pancreatic secretions, aiding diagnosis of gastrinoma, and facilitating certain endoscopic procedures. It is regulated as a prescription drug and obtained only through licensed healthcare channels.
Importantly, approval is limited to these diagnostic uses. There is no approved therapeutic indication for secretin in autism or other behavioral conditions, and the research does not support such use. Marketing or selling secretin for unproven purposes would fall outside its regulatory authorization.
Because it is a clinician-administered diagnostic agent rather than a consumer product, secretin is not sold as a dietary supplement and is not available over the counter. Its status reflects a narrow, well-defined medical role supported by long-standing physiological understanding.
Frequently asked questions
Is secretin a treatment for autism?
No. Although it was studied extensively for autism after early anecdotal reports, multiple randomized controlled trials found no benefit, and it is not an effective or approved treatment for autism.
What is secretin actually used for today?
It is used as a diagnostic agent to stimulate and measure pancreatic secretion, to help diagnose gastrinoma, and to assist certain endoscopic procedures.
Why is secretin historically important?
Discovered in 1902, it was the first hormone ever identified and led to the very concept of hormones as chemical messengers carried in the blood.
Can I buy secretin as a supplement?
No. It is a prescription diagnostic drug administered by clinicians in a medical setting and is not sold as a supplement or over the counter.
How is secretin given?
It is administered intravenously by trained healthcare professionals as part of a monitored diagnostic procedure, not taken at home.
References
Each source links to its original record — peer-reviewed studies, regulator pages, or reference texts, labelled by type. We summarize findings neutrally; a citation is a reference, not an endorsement, and not a claim that its authors reviewed this page.
- Chu JY, Yung WH, Chow BK. Secretin: a pleiotrophic hormone. Ann N Y Acad Sci. 2006. Peer-reviewed study
- Henriksen JH, Schaffalitzky de Muckadell OB. [Secretin--the first hormone]. Ugeskr Laeger. 2002. Peer-reviewed study
- Häcki WH. Secretin. Clin Gastroenterol. 1980. Peer-reviewed study
- Miyoshi A. [Secretin]. Horumon To Rinsho. 1972. Peer-reviewed study
- Schnabl K, Li Y, U-Din M, et al. Secretin as a Satiation Whisperer With the Potential to Turn into an Obesity-curbing Knight. Endocrinology. 2021. Peer-reviewed study
- Chey WY, Chang TM. Secretin: historical perspective and current status. Pancreas. 2014. Peer-reviewed study