What the label states, the lot delivers — net peptide mass, not gross powder weight, purity reported as measured rather than rounded up, and a Certificate of Analysis for every lot.
Net peptide mass, not powder weight; purity as measured, not rounded up; a COA per lot.
Net peptide + purity not rounded up. COA per lot.
FDA PCAC reviews 7 peptides for the 503A bulks list (BPC-157, KPV, TB-500, MOTs-C, Emideltide, Semax, Epitalon). Read our compounder's decision tree. Read our briefing →
FDA PCAC reviews 7 peptides for the 503A bulks list in July. Read →
FDA PCAC: 7 peptides under review. Read →
Pineal hormone · sleep / circadian-rhythm research compound
Overview
Melatonin (N-acetyl-5-methoxytryptamine) is an endogenous indoleamine neurohormone synthesized and secreted by the pineal gland in darkness, and is also present in peripheral tissues such as the retina and gastrointestinal tract. Its secretion is governed by the light-dark cycle, making it the core chemical signal of the mammalian circadian rhythm. As a non-peptide small molecule, it is commonly used as a reference/control standard or as an experimental reagent in neuroendocrine, antioxidant, and circadian-rhythm research. In the United States it is regulated as a dietary supplement (no FDA premarket approval), whereas the EU, UK, Japan, and Australia classify it as a prescription drug. Vialdyne releases Melatonin as a lyophilized small molecule (indoleamine hormone) against a ≥ 99.0% HPLC main-peak specification, with a batch-specific Certificate of Analysis covering RP-HPLC purity, mass-spec identity, water content, residual solvents, and endotoxin. Sequence / identity confirmation is documented on the released lot.
Applications & buyer fit
Cognitive and neuropeptide buyers are predominantly research labs running in vivo rodent studies. The dominant administration route in the literature is intranasal, these peptides are not meaningfully blood-brain-barrier permeable when delivered systemically. For in vivo workflows, endotoxin and microbial-limit testing is recommended at the COA stage so the bioassay readout is not confounded by contamination unrelated to the test article.
Sourced for
Buyer fit
Documentation that ships
Procurement note: For in vivo workflows, endotoxin and microbial-limit testing on the specific lot is recommended at the COA stage.
Primary buyer fit: academic and contract research laboratories.
Specifications
Regulatory note
Research-use-only reference material; not for human or veterinary use.
Selected literature
Frequently asked questions
Melatonin is an indoleamine derived from tryptophan, so it is characterized like a small-molecule API, not a peptide. Its release file relies on RP-HPLC for chromatographic purity, UV-Vis for identity, and residual-solvent profiling, with no mass-spec sequence verification because there is no sequence to verify. A buyer should not accept a peptide-style packet, HPLC plus mass spec plus sequence confirmation, as adequate qualification here, nor apply peptide net-content conventions. Aligning the incoming-inspection template to a small-molecule specification prevents mismatched acceptance criteria when melatonin is co-stocked alongside peptide longevity materials.
Melatonin degrades under visible and ultraviolet light, generating kynuramine-type breakdown products; this proceeds fastest in solution but also affects the solid on prolonged exposure. The practical control is amber or opaque containers and storage in the dark between uses rather than clear glass on an open bench. Protected from light, the lyophilized solid is stable across the standard two-year re-test window at room temperature, with refrigeration extending margin but not being strictly required for the solid form. A qualification file should record the light-protection requirement and the re-test date so shelf-life is auditable.
