Buy Orexin B Research Peptide
Supplied as a lyophilized powder and independently verified to ≥98% purity by HPLC and MS-UPLC analysis.
Buy Orexin B Research Peptide
Supplied as a lyophilized powder and independently verified to ≥98% purity by HPLC and MS-UPLC analysis.
HPLC Verified
≥98% purity
Lyophilised
Powder format
Express Shipping
Cold-chain included
COA Available
Every batch
Next batch coming soon
This compound is temporarily out of stock. Check back soon or contact us for a restock estimate.
HPLC Verified
≥98% purity
Lyophilised
Powder format
Express Shipping
Cold-chain included
COA Available
Every batch
Next batch coming soon
This compound is temporarily out of stock. Check back soon or contact us for a restock estimate.
Verify Batch
Lot-level COA, Batch DF/ORB/062026
What is Orexin B?
Orexin B is the second orexin brain peptide, with 28 amino acids. Both orexins govern wakefulness and appetite, but Orexin B prefers the OX2 receptor, making it a more precise tool for studying that part of the system in animal research.
- A brain peptide studied for its role in sleep-wake and alertness signaling
- More selective for the OX2 receptor, useful for separating receptor-specific effects
- Studied in animal research on sleep-wake regulation and feeding
- Used to map how the two orexin receptors contribute to sleep and alertness
For research use only. Not approved for human therapeutic use.
Orexin B (CAS 205640-91-1), also known as Hypocretin-2, is a synthetic 28-amino acid neuropeptide with a molecular weight of 2937.42 g/mol. Unlike Orexin A, Orexin B is a linear peptide with no intramolecular disulfide bridges and no pyroglutamyl modification. While Orexin A and Orexin B share 46% sequence homology within their C-terminal regions, their structural divergence leads to distinct receptor selectivity profiles. Produced via solid-phase peptide synthesis, Hypocretin-2 acts as an endogenous agonist with high selectivity for the OX2R receptor in preclinical neuroscience research.
Orexin B has been investigated as a ligand of the orexinergic system, and its differential receptor selectivity has been characterized for dissecting OX1R- versus OX2R-mediated signaling. The discovery study identified Orexin B as a co-derived product of the prepro-orexin precursor localized to neurons of the lateral and posterior hypothalamus, with central administration of orexin peptides shown to stimulate feeding behavior in rats [1]. In vivo rodent studies have used Orexin B as a comparator to Orexin A in central and basal forebrain microinjection studies, showing that Orexin A was more potent than Orexin B at inducing wakefulness, with robust wake-promoting effects localized to the medial septal area, medial preoptic area, and substantia innominata [2], making Orexin B a reference compound in orexin research as a comparator peptide for probing Orexin A/Orexin B potency differences in sleep-wake regulation and arousal state transitions.
Orexin B is produced to research-grade standards and independently verified by third-party HPLC and MS-UPLC analysis before dispatch. Vials are vacuum sealed and stored in a temperature controlled, monitored cold storage system. Certificates of Analysis are available to view and download directly on the product page.
Sold strictly for in vitro research purposes only. Not for human consumption. Intended for use by qualified researchers in laboratory settings only.
References
Scientific Review
Dr. Martina Rossi, PhD
Scientific Contributor and Reviewer
Reviewed for scientific accuracy, 14 June 2026
Lyophilised powder: store at -20 °C or below, away from light and moisture. Once reconstituted in an appropriate laboratory diluent (e.g. sterile water, PBS, or assay buffer), store at 2–8 °C and use within the validated period for your protocol. Do not refreeze.
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Quality Guaranteed
Every batch is HPLC-tested to ≥98% purity. Certificate of Analysis available on this page; MSDS available on request.