Peptide therapy research: how the field has evolved since 1921

A hundred-year arc from one peptide to more than a hundred.

TL;DR

• Peptide medicine started in 1921 with insulin — a peptide drug that has saved millions of lives.
• More than 100 peptide-based drugs are now approved globally, with another 150+ in clinical trials.
• The GLP-1 boom has pulled peptide medicine into the mainstream, but the field has been growing steadily for a century.

What it is

Peptide therapy is the use of short chains of amino acids — typically between 2 and 50 amino acids long — as medicines. The first one was insulin, isolated by Frederick Banting and Charles Best at the University of Toronto in 1921. Within two years, insulin was a commercial product and the work won the 1923 Nobel Prize in Physiology or Medicine (Nobel Foundation).

How it works

Think of the body’s hormones, signals, and messengers as a postal service. Most of the letters are peptides — short, specific, addressed to one receptor. Peptide drugs are essentially copies or close cousins of those letters. They bind a specific receptor (the lock) the way the original signal does (the key). That is why peptide drugs tend to have narrower effects than small-molecule drugs, which often act on many locks at once.

Who asks about it

People come to this topic after hearing the word “peptide” used in two very different ways. One use is the GLP-1 weight-loss conversation. The other is the wellness-and-longevity register on podcasts. Both are real. Both are downstream of the same hundred-year scientific arc. Understanding the history helps tell the difference between a well-studied drug class and a new fad.

What the research says

A 2020 review in Signal Transduction and Targeted Therapy counted more than 80 approved peptide drugs at that point and 170+ in clinical trials (Wang et al., 2020). Two technical leaps moved the field forward. Solid-phase peptide synthesis (developed by Bruce Merrifield, Nobel Prize 1984) made manufacture much faster. Recombinant DNA production (1970s onward) enabled larger peptides like growth hormone and insulin analogs. The pipeline has expanded into oncology, metabolic disease, and rare conditions.

What to know before considering it

The word “peptide” covers everything from insulin to small research compounds with thin human data. Not all peptides are alike. FDA-approved peptide drugs go through full clinical trials. Compounded peptides — including some discussed widely on social media — are prepared by state-licensed 503A pharmacies and are not themselves FDA-approved. Any peptide access requires a licensed clinician.

The Halftime POV

A hundred-year story is harder to mythologize. Peptide medicine is a well-established branch of pharmacology, not a fringe wellness trend. The interesting question is which peptides have enough human data to belong in proactive medicine — and which are still research compounds. That distinction is the whole game.

Related reading:

• What are peptides? A plain-English primer
• Peptides vs hormones: the overlap and the distinction
• The ‘banned overnight’ myth: what actually happened to peptides in 2023

FAQ

Q: What was the first peptide drug? A: Insulin, isolated by Banting and Best in 1921. It went into commercial use within two years and earned the 1923 Nobel Prize in Physiology or Medicine.

Q: How many peptide drugs are on the market today? A: More than 100 peptide-based drugs have been approved globally, with another 150+ in clinical trials. Roughly two-thirds of approved peptides treat metabolic, cardiovascular, or oncology conditions.

Q: Why is peptide therapy getting so much attention now? A: GLP-1 agonists like semaglutide and tirzepatide moved peptides into mainstream metabolic care. Improved synthesis methods and new delivery routes have also lowered the cost of bringing peptide drugs to market.

Q: Are most peptide drugs FDA-approved? A: Most commercially available peptide drugs are FDA-approved. Compounded peptides — including some discussed in the wellness space — are prepared by state-licensed 503A pharmacies and are not themselves FDA-approved.

Disclaimer

This article is educational and is not medical advice. Compounded medications are not FDA-approved. Clinical outcomes depend on individual factors and require physician evaluation. Results vary. Halftime Health is launching soon — join the waitlist to get updates.

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Sources

• Nobel Prize in Physiology or Medicine 1923 — Frederick G. Banting and John Macleod for the discovery of insulin
• Wang L et al., “Therapeutic peptides: current applications and future directions,” Signal Transduction and Targeted Therapy (2020)