PinnyPeptide

Orexin-A vs Orexin-B

Side-by-side comparison: effects, dosing ranges, side effects, regulatory status, and reconstitution.

Peptide A

Orexin-A

Sleep

Hypothalamic wake-promoting neuropeptide — the molecule lost in narcolepsy type 1.

Peptide B

Orexin-B

Sleep

Wake-promoting neuropeptide selective for OX2R — the receptor most central to narcolepsy.

Typical vial

5 mg

Typical dose

20-80 (intranasal) mcg

Half-life

~30-60 minutes (CSF)

FDA status

Not FDA approved as a therapeutic. Orexin receptor antagonis…

Typical vial

5 mg

Typical dose

Variable (research) mcg

Half-life

~30 minutes

FDA status

Not FDA approved.

Orexin-A effects

  • Promotes wakefulness and arousal
  • Activates OX1R and OX2R receptors
  • Stimulates monoaminergic arousal centers
  • Increases attention and cognitive performance during wake
  • Modulates feeding behavior and reward processing

Orexin-B effects

  • Selective activation of OX2R (over OX1R)
  • Promotes wakefulness and arousal
  • Stabilizes wake state (anti-cataplectic)
  • Modulates feeding behavior (less than OX1R-mediated)
  • Investigational target for narcolepsy treatment

Orexin-A side effects

  • Insomnia / sleep disruption (intended effect)
  • Anxiety or jitteriness at high doses
  • Increased blood pressure and heart rate (transient)
  • Theoretical: enhanced reward sensitivity / addiction risk
  • Limited safety data for chronic human use

Orexin-B side effects

  • Sleep disruption (intended effect)
  • Anxiety or restlessness at high doses
  • Limited safety data for chronic human use
  • Possible enhanced reward / addiction concerns

Orexin-A dosing ranges

Intranasal arousal research

20-80 mcg · As needed for wakefulness · Acute use

Animal research

Variable per protocol · ICV or IV · Per protocol

Orexin-B dosing ranges

Animal research

Variable per protocol · ICV or IV · Per protocol

Full Orexin-A guide → Full Orexin-B guide →

Orexin-A vs Orexin-B — common questions

What is the difference between Orexin-A and Orexin-B?

Orexin-A: Hypothalamic wake-promoting neuropeptide — the molecule lost in narcolepsy type 1. Typical dose 20-80 (intranasal) mcg. Orexin-B: Wake-promoting neuropeptide selective for OX2R — the receptor most central to narcolepsy. Typical dose Variable (research) mcg. Both fall under the Sleep category.

Can you stack Orexin-A and Orexin-B?

Stacking Orexin-A with Orexin-B is a protocol-design question best raised with a clinician — it depends on your goal, current bloodwork, and whether both peptides target overlapping mechanisms. Both peptides should be tracked independently with separate injection sites and timing. PinnyPeptide supports multi-peptide stacks with automatic injection site rotation.

Which is dosed more frequently, Orexin-A or Orexin-B?

Orexin-A is typically dosed: As needed for wakefulness for Intranasal arousal research; ICV or IV for Animal research. Orexin-B is typically dosed: ICV or IV for Animal research.

Are Orexin-A and Orexin-B FDA approved?

Orexin-A: Not FDA approved as a therapeutic. Orexin receptor antagonists (suvorexant, lemborexant, daridorexant) are FDA-approved for insomnia. Orexin-B: Not FDA approved.

Related peptide comparisons

dsip vs orexin-adsip vs orexin-b

Tracking either of these?

Log doses, automate injection site rotation, and never lose track of where you last pinned. Free forever.

Get Started Free