Peptides (Overview)

What they are

Peptides are short sequences of amino acids, typically <50 residues. In longevity-adjacent contexts the term usually refers to a heterogeneous set of compounds — some FDA-approved (semaglutide, tirzepatide, teriparatide), many investigational or unapproved — including BPC-157, TB-500, GHK-Cu, the thymosin family, and growth-hormone secretagogues such as ipamorelin and CJC-1295.

Why they’re of interest

Peptide signalling is highly specific. The clearly approved peptide drugs (GLP-1/GIP agonists, PTH analogs) have transformed metabolic and bone medicine, and some interest in “research peptides” for healthspan derives from extrapolation of those successes.

State of evidence

A small number have robust evidence:

• GLP-1 agonists (semaglutide, liraglutide) reduce major cardiovascular events in obese and diabetic populations and improve multiple cardiometabolic risk factors.
• GIP/GLP-1 agonists (tirzepatide) extend that profile.
• Teriparatide (PTH 1–34) treats severe osteoporosis.

Many other “longevity peptides” sold through grey-market suppliers have little human evidence and significant regulatory and contamination risk.

Safety

This area is dominated by regulatory and supply-chain risk as much as pharmacology. Many products are sold as “not for human use” research chemicals. Off-label injectable use without clinician supervision carries infection, allergic-reaction, and dosing-error risks. Growth-hormone modulation has theoretical cancer-progression concerns.

Related entries

See also: Altered intercellular communication, Peter Attia.