What was the first hormone ever discovered?

Secretin, in 1902. Bayliss and Starling showed that the pancreas responded to acid in the intestine even when the nerves between them had been cut, proving a chemical message had crossed the gap. The word "hormone" was coined shortly afterwards.

What was the first peptide to be synthesised?

Oxytocin, by Vincent du Vigneaud in 1953. It earned the Nobel Prize in Chemistry in 1955 and marked the shift from extracting peptides from tissue to building them from scratch.

Why did Russian and Western peptide research develop separately?

They pursued different approaches with little exchange of literature. Western pharmacology focused on receptor-targeted drug development; the Soviet programme under Khavinson spent four decades on short peptides extracted from organ tissue. That separation is a major reason the bioregulator evidence base still looks unusual from a Western standpoint.

How long does it usually take a peptide to go from discovery to use?

Typically decades. Twenty-two years separated the discovery of the first hormone from insulin becoming a treatment; fifteen separated GHRP-6 from the discovery of ghrelin; GLP-1 was characterised in the 1980s and semaglutide was approved in 2017.

Research Library›Foundations›A Century of Peptide Science

History

A Century of Peptide Science: From Secretin to the Triple Agonists

The field began in 1902 with an experiment that overturned how the body was thought to communicate. Everything in this library sits somewhere on the line that followed.

8 min read·4 studies cited·Updated July 2026

Quick Reference

First hormone identified	1902 — secretin
First peptide synthesised	1953 — oxytocin
Nobel Prizes in this story	Four, at minimum
Bioregulator programme begins	1973
Approved peptide drugs today	Over 80 worldwide

Why the History Helps

Peptide research can look like a scatter of unrelated compounds with awkward names. It is not. Almost everything in this library descends from a handful of moments when someone noticed something they were not looking for, and the field reorganised itself around what they found.

The through-line, in plain language: for most of medical history the body was assumed to be run by the nervous system — wires carrying instructions, like a building with a bell in every room connected to a switchboard. The peptide story begins the moment someone proved that a message had travelled with no wire attached. Everything after that is the slow working-out of a second communication system, one that runs on chemistry rather than cabling, and of how to write messages in that language ourselves.

The Timeline

1902

Secretin — the first hormone

Bayliss and Starling in London show that the pancreas responds to acid in the intestine even when every nerve between them is cut. A chemical message had crossed the gap. The word "hormone" is coined shortly after, and chemical signalling enters biology.

1921

Insulin isolated

Banting and Best extract insulin in Toronto. The first peptide hormone put to widespread medical use, and proof that a signalling molecule could be given as a treatment.

1953

Oxytocin synthesised

Vincent du Vigneaud synthesises oxytocin — the first peptide hormone ever made from scratch in a laboratory. It earns the Nobel Prize in Chemistry in 1955 and turns peptides from things to be extracted into things that can be built.

1970

VIP isolated

Said and Mutt isolate vasoactive intestinal peptide from intestinal tissue, one of a wave of gut peptides found in this period that turn out to act throughout the body.

1973

The bioregulator programme begins

Vladimir Khavinson starts work in Leningrad on short peptides extracted from organ tissue, initially for Soviet military medicine. The programme runs for four decades and produces Thymalin, Epithalamin, Cortexin and eventually Epitalon.

1977

DSIP and the sleep peptides

Delta sleep-inducing peptide is isolated from rabbit brain, part of a period in which researchers begin finding peptides that shape behaviour and state rather than simply metabolism.

1982

GHRH characterised

Growth hormone-releasing hormone is identified and sequenced. Sermorelin, CJC-1295 and Tesamorelin are all eventually built from this molecule.

1984

GHRP-6 and a prediction

Cyril Bowers develops GHRP-6, which releases growth hormone through a receptor nobody can identify. He argues the body must produce its own molecule for that receptor. He is right, but the proof takes fifteen years.

1994

Semax registered in Russia

The ACTH(4–7) analogue Semax enters Russian medical practice, part of a parallel tradition of peptide development running largely separate from Western pharmaceutical research.

1999

Ghrelin found

Kojima and colleagues identify ghrelin, the natural hormone for the receptor GHRP-6 had been triggering since 1984. Bowers’ prediction is confirmed, and hunger signalling is opened up as a research field.

2001

Humanin — mitochondria speak

A peptide is found encoded not in nuclear DNA but in the mitochondrial genome. Mitochondria are revealed to send outward signals, not merely produce energy. MOTS-c follows in 2015.

2003

Epitalon and telomerase

Khavinson and colleagues report telomerase activation and telomere elongation in human cell culture — the bioregulator programme’s most cited and most debated result.

2005

The incretin era opens

Exenatide, the first GLP-1 receptor agonist, is approved. The mechanism that will later produce semaglutide, tirzepatide and retatrutide enters clinical use.

2017

Semaglutide approved

Approved for type 2 diabetes, and for weight management in 2021. The compound reframes the metabolic field and becomes the reference standard every newer agonist is measured against.

2022

Dual agonism arrives

Tirzepatide is approved for type 2 diabetes, adding GIP alongside GLP-1 — the first compound to show that acting on two incretin receptors outperforms one.

2023

Triple agonism reported

Retatrutide Phase 2 results are published, adding glucagon to GIP and GLP-1 and reporting the largest weight effect recorded for a peptide to that point. The compound remains investigational.

Three Patterns Worth Noticing

The best findings were mostly accidents. Secretin was found while investigating nerves. GHRP-6 came out of work on opioid-related molecules. Humanin turned up in surviving brain tissue from an Alzheimer’s patient. The field has advanced less by designing what it wanted than by noticing results that did not fit.

Two traditions ran in parallel and barely spoke. While Western pharmacology pursued receptor-targeted drug development, the Soviet programme spent four decades on organ-derived short peptides. Neither tradition read much of the other’s literature, which is a large part of why the bioregulator evidence base still looks so unusual from a Western standpoint — and why so much of it remains unreplicated.

The gap between discovery and use is long. Twenty-two years separated the first hormone from insulin as a treatment. Fifteen separated GHRP-6 from ghrelin. GLP-1 was characterised in the 1980s and semaglutide arrived in 2017. A compound generating excitement today is likely to be somewhere in the middle of a similar span.

Frequently Asked Questions

Compiled by the Southern Pacific Labs research team. Last updated July 2026.

Browse the research range →

Published References

Bayliss WM, Starling EH. “The mechanism of pancreatic secretion.” The Journal of physiology, 1902. PubMed
du Vigneaud V, Ressler C, Swan JM, et al. “The synthesis of an octapeptide amide with the hormonal activity of oxytocin.” Journal of the American Chemical Society, 1953. Source
Kojima M, Hosoda H, Date Y, et al. “Ghrelin is a growth-hormone-releasing acylated peptide from stomach.” Nature, 1999. PubMed
Wang L, Wang N, Zhang W, et al. “Therapeutic peptides: current applications and future directions.” Signal transduction and targeted therapy, 2022. PubMed