A Century of Peptide Drugs: The Timeline

• 1921: insulin — first peptide drug, proof of concept for the entire field.
• 1954: du Vigneaud synthesizes oxytocin/vasopressin — synthetic = real.
• 1963: Merrifield's solid-phase synthesis — the manufacturing unlock.
• 1980s→now: recombinant production, then the GLP-1 boom. 80+ approved.

Understanding where the field came from explains why today's peptides look the way they do. Four inflection points did most of the work.

1921 — Insulin: proof peptides can be drugs

Banting and Best isolated insulin in 1921; it was commercialized by 1923 (Wang et al.). This established the recurring themes of the field — high potency, high specificity, and demanding manufacturing.

1954 / 1963 — Synthesis becomes possible, then scalable

Du Vigneaud's 1954 total synthesis of oxytocin and vasopressin proved that synthetic peptides reproduce endogenous activity (Muttenthaler et al.). Merrifield's 1963 invention of solid-phase peptide synthesis (SPPS) automated assembly on a solid support — the single biggest manufacturing unlock in the field's history (Muttenthaler et al.).

1980s — Recombinant production

Recombinant technology enabled clean production of larger peptides at scale, and conjugation strategies (lipids, PEG) began solving the renal-clearance / short-half-life problem (Muttenthaler et al.). This is the lineage behind every long-acting analog today.

Now — The GLP-1 era and what's next

80+ peptide drugs are approved (Wang et al.), with insulin and GLP-1 agonists dominating revenue (Muttenthaler et al.). The frontier: oral GLP-1s, multi-receptor agonists, and AI-designed sequences.

Key takeaways

• The field rests on four unlocks: isolation, synthesis, SPPS, and recombinant production.
• SPPS (1963) is the manufacturing backbone of modern peptides.
• Half-life engineering (lipids/PEG) traces to the post-1980s era.
• GLP-1s are the current peak, not the endpoint.