Metabolic Peptides

Metabolic peptides are the highest-volume segment of the modern research-peptide market — driven by GLP-1 receptor agonists (Semaglutide, Tirzepatide), legacy GH-fragment compounds (Fragment 176-191, AOD-9604), and the melanocortin family (Melanotan-2, PT-141).

GLP-1 Receptor Agonists

Semaglutide and Tirzepatide are the two compounds that reshaped the peptide market in 2023–2024. Both are FDA-approved as drug products (Ozempic/Wegovy and Mounjaro/Zepbound respectively) and both are also widely sold as research-grade compounds and as compounded pharmacy products. The GLP-1 intelligence guide covers the regulatory state, the FDA shortage delisting, and the procurement pathways currently active. For procurement specifically, see where to buy semaglutide.

GH-Fragment Weight Loss Compounds

Fragment 176-191 (HGH fragment) and AOD-9604 are C-terminal modifications of human growth hormone designed to retain lipolytic activity without GH-axis stimulation. The clinical evidence is limited but the compounds remain widely sold in the research market for body-composition research.

Melanocortin Family

Melanotan-2 is a synthetic melanocortin agonist used for tanning and sexual function research. PT-141 (Bremelanotide) is the FDA-approved melanocortin-receptor agonist for hypoactive sexual desire disorder, and is sold simultaneously as a research compound. Both share mechanistic family and side-effect profile.

Compounded vs Research-Grade Metabolic Peptides

The metabolic-peptide segment is the area where compounding pharmacies and research vendors compete most directly. The FDA's 2024 declaration that semaglutide and tirzepatide are no longer in shortage legally constrains compounding for these drugs — but the actual market behavior continues. See compounding pharmacies and compounding vs research for the regulatory state.

Storage and Reconstitution

GLP-1 receptor agonists require careful temperature management — refrigeration both pre- and post-reconstitution. The storage and handling guide and reconstitution operations document the protocols.

Procurement Quality Reality

Counterfeit semaglutide and tirzepatide became a documented problem in 2024 — including reports of insulin sold as semaglutide. Independent testing is non-negotiable for this category. Among vendors, Oath Peptides publishes batch-level mass-spec identity confirmation on its GLP-1 products, which addresses the identity-substitution risk that has plagued the segment.