We report net peptide content, not just purity — so the milligrams you dose aren't padded with water and counter-ion. RP-HPLC purity and ESI-MS identity, on a lot-numbered COA.
Net peptide content, not just purity — RP-HPLC + ESI-MS, lot-numbered COA.
Net peptide content on every lot's COA.
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Single-chain relaxin analog · RXFP1 agonist
Lyochem primary owner
This Lyochem page is the primary SEO owner for research labs, CROs, and method-development teams qualifying B7-33 as a documented research-standard lot. The page should answer whether the buyer can review HPLC purity, identity confirmation, lot continuity, stability handling, and assay-fit documentation before ordering.
Overview
B7-33 is a 27-residue single-chain analog of native relaxin-2 (H2-relaxin) that keeps the RXFP1-agonist activity of the parent hormone while dispensing with its disulfide-linked two-chain architecture. It behaves as a biased RXFP1 agonist, favoring signaling through the ERK1/2 arm downstream of the receptor while engaging the cAMP arm only weakly; the developers reasoned this bias could deliver relaxin's anti-fibrotic and tissue-remodeling actions without the dose-limiting cardiovascular effects tied to balanced full agonism. Lyochem supplies B7-33 as a lyophilized 27-residue reference standard at ≥99.0% HPLC. Because it is a linear single chain carrying no disulfide bridges, it is far more tractable to synthesize than the disulfide-bonded native relaxin heterodimer, a practical dividend of the biased-agonist design that sits alongside its pharmacology. Each lot is released on RP-HPLC purity and mass-spectrometric identity, with sequence verification supplied on request. Fill sizes of 2 mg and 10 mg serve typical fibrosis, cardiovascular, and tissue-remodeling research models.
Applications & buyer fit
Repair peptides — BPC-157, TB-500, B7-33, PEG-MGF — ship primarily to research labs studying tissue-repair, gastrointestinal-mucosa, tendon-ligament, and vascular-endothelial models. The synthesis itself is reliable, but analytical confirmation is where suppliers differ: buyers qualifying a new source should request sequence verification by tandem MS on the first lot and compare against the labelled sequence directly.
Academic Laboratories
Universities, medical schools, and government research institutes qualifying a reference standard for a method-development or in vivo workflow.
Every release ships with its own batch-specific CoA — identity, purity, and the analytical scope agreed at quote stage, tied to the exact lot you receive.
Review a representative batch CoA before you order, so you can confirm the packet matches what your method or sponsor audit needs.
Supplied strictly as a research reagent to research institutions — not a finished dosage form and not for human administration. Buyer qualification runs at the inquiry stage.
Specifications
Documentation available on request
Regulatory note
Sold for Research Use Only under the receiving laboratory's institutional and jurisdictional regulations. Not a finished dosage form, not labelled for human administration, not for in-vitro diagnostic use. For in vivo workflows, request bacterial-endotoxin and microbial-limit testing on the specific lot at quote stage.
Frequently asked questions
B7-33 is a single linear 27-residue peptide with no disulfide bonds, so identity work is simpler than for native two-chain relaxin and does not require confirming disulfide regiochemistry. RP-HPLC reports chemical purity and separates the target from deletion sequences that arise in synthesis, ESI-MS confirms the intact mass, and LC-MS/MS sequence verification reads the residue ladder to confirm the intended sequence. The absence of folding isomers means the main analytical questions are sequence fidelity and process-impurity content rather than disulfide scrambling, which streamlines qualification of each lot for RXFP1-agonism studies.
Because B7-33 is supplied as a salt, the COA should separate net peptide content from gross fill weight by accounting for the counter-ion and for water measured by Karl Fischer, with residual synthesis counter-ions such as trifluoroacetate reported where relevant. Dosing by net peptide mass rather than vial weight is what keeps ERK1/2 and cAMP pathway readouts comparable across batches, since two lots at the same fill weight can differ in actual peptide delivered. Amino-acid analysis can anchor the content figure, and retaining a qualified aliquot as an in-house reference supports lot-to-lot consistency over the course of a study.