Orexin A human, rat, mouse

≥97% (HPLC)

Hypocretin 1
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
MDL number:
Pricing and availability is not currently available.

Quality Level




≥97% (HPLC)




1% acetic acid: 1.00-1.04 mg/mL, clear, colorless
water: 1.00-1.04 mg/mL, clear, colorless

shipped in


storage temp.




InChI key


Gene Information

human ... HCRT(3060)
mouse ... Hcrt(15171)
rat ... Hcrt(25723)

Amino Acid Sequence

Glp-Pro-Leu-Pro-Asp-Cys-Cys-Arg-Gln-Lys-Thr-Cys-Ser-Cys-Arg-Leu-Tyr-Glu-Leu-Leu-His-Gly-Ala-Gly-Asn-His-Ala-Ala-Gly-Ile-Leu-Thr-Leu-NH2 [Disulfide Bridges: 6-12; 7-14]

General description

Orexin A, also known as hypocretin 1 (hcrt1), is a 33 amino acid excitatory neuropeptide, localized in a small set of neurons in the perifornical area of the hypothalamus. It is synthesized from the precursor protein prepro-orexin in neurons. Orexin A binds to its G-protein-coupled receptor orexin-1 (OX1) which is also called as hcrt receptors 1 (hcrtr1).
Orexin A is characterized with an N-terminal pyroglutamyl residue, two intramolecular disulfide bridges and a C-terminal amidation.


Orexin A has been used to study its effect on serum luteinizing hormone (LH) concentration in lateral ventricle in ovariectomized (OVX) gilts and is used to study the behavioral and metabolic effects of central injections of orexin A on pigeons (Columba livia).
Orexin A human, rat, mouse has been used to study its effect on the functioning of porcine pancreatic islets. It has also been used as an orexin receptor 1 (OX1R) antagonist to study the effect of orexin systems in the effect of etonogestrel on respiratory response to prolonged metabolic acidosis.

Biochem/physiol Actions

Orexins (hypocretins) comprise a family of hypothalamic peptides that are involved in the initiation of sleep and in feeding behavior. Orexin A stimulates food intake through activation of the OX1 receptor. Orexin B activates OX2 receptors. Both OX1 and OX2 receptors are involved in maintaining arousal. OX2 receptors appear to be inhibitory autoreceptors on orexin-containing neurons.
Orexins plays a vital role in several physiological functions including feeding, neuroendocrine regulation and arousal. In addition to this, it is also associated with the pathophysiology of narcolepsy. Orexin A, expressed in locus coeruleus (LC) area, binds to orexin-1 (OX1) receptor and regulates rapid eye movement (REM) sleep by acting on the firing rate of noradrenergic neurons. Orexin A release is regulated by suprachiasmatic nucleus (SCN).

Other Notes

Lyophilized from 0.1% TFA in H2O

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis
Certificate of Origin
Orexin A modulates endocrine function and viability of porcine pancreatic islets
Sassek M, et al.
Journal of Physiology And Pharmacology, 68, 815-821 (2017)
Tao Li et al.
Journal of neuroinflammation, 17(1), 187-187 (2020-06-17)
Orexins are two neuropeptides (orexin A, OXA; orexin B, OXB) secreted mainly from the lateral hypothalamus, which exert a wide range of physiological effects by activating two types of receptors (orexin receptor 1, OXR1; orexin receptor 2, OXR2). OXA has...
Hypocretin-1 modulates rapid eye movement sleep through activation of locus coeruleus neurons.
Bourgin P
The Journal of Neuroscience, 20(20), 7760-7765 (2000)
Orexin and central regulation of cardiorespiratory system
Vitamins & Hormones, 89, 159-184 (2012)
Lesions of the suprachiasmatic nucleus eliminate the daily rhythm of hypocretin-1 release.
Zhang S
Sleep, 27(4), 619-627 (2004)

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