Orexin B (Hypocretin-2)
Also known as Orexin-B · Hypocretin-2 · OR-B
New
Reconstitution & dosing guide
5 mg vial — research phases, recon steps, and a live unit calculator.
Available sizes & price
Catalog only5mg x 10 vials
Orexin B · Not in current stock
$65 / vial
Prices per vial · Research use only · Not medical advice.
Endogenous 28-amino-acid lateral-hypothalamic neuropeptide that preferentially activates OX2R to stabilize wakefulness, appetite, and arousal circuits.
How to picture it
Orexin systems help keep the brain in "awake, attentive, motivated" mode. Orexin B is a native-type signal in that vigilance network. Picture the brain's "stay alert and seek" channel — research clusters around sleep/wake integrity and arousal chemistry, the difference between being up and being truly online.
Research focus & benefits
- Sleep/wake and vigilance pathway research
- Appetite and arousal orexin biology
- Narcolepsy-related pathway science context
Benefits describe research interest and pathway rationale — not guaranteed outcomes or medical advice. Research use only.
Overview
Orexin B is one of two orexin/hypocretin peptides cleaved from prepro-orexin. Loss of orexin neurons causes narcolepsy type 1. Orexin B prefers OX2R (~100-fold over OX1R), the receptor most critical for wake stability. Pharmaceutical development has focused more on small-molecule OX2R agonists for narcolepsy than on the native peptide, which has poor systemic BBB utility.
Mechanism
OX2R (and weaker OX1R) GPCR agonism on histaminergic TMN, noradrenergic LC, serotonergic raphe, and cholinergic arousal nuclei. Also modulates feeding and reward circuitry. Cardiac OX2R research suggests possible cardioprotective orexin-B signaling distinct from orexin-A.
Research uses
- Narcolepsy and wake-stability models
- Appetite and reward pathway research
- Functional cardiac orexin receptor studies
- Comparison baseline for synthetic OX2R agonists
Research dosing notes
Native peptide is research-only with central administration in animal work. Not a practical peripheral nootropic. Emerging small-molecule OX2R agonists are the clinical path.
Half-life / kinetics
~5–10 minutes (rapid peptidase degradation)
Common research routes
Reported considerations
- Arousal/insomnia if central
- Cardiovascular effects theoretical
- No peripheral bioavailability
Contraindications / cautions
- Narcolepsy patients need approved care
- Pregnancy
- Do not self-treat sleep disorders
Common research stacks
- Semax
- PE-22-28
- DSIP (opposing sleep angle)
Legal / access note
Endogenous research neuropeptide; not an approved wake-promoting drug. Dual orexin receptor antagonists are the approved insomnia class (opposite direction).