Orexin-A
A neuropeptide that regulates wakefulness, arousal, and appetite. Its deficiency causes narcolepsy.
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This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician
What is Orexin-A?
Orexin-A (also called Hypocretin-1) is a 33-amino acid neuropeptide produced by neurons in the lateral hypothalamus. It is a master regulator of the sleep-wake cycle, arousal, and energy homeostasis. Loss of orexin-producing neurons causes narcolepsy type 1. Research into orexin replacement therapy and orexin receptor agonists is active.
Why People Talk About It
Narcolepsy treatment (orexin replacement)
EmergingWakefulness and alertness promotion
EmergingAppetite and metabolism regulation
EmergingHow It Works
Orexin-A is the brain's 'wake-up signal.' It activates arousal centers throughout the brain, keeping you alert and awake. When orexin neurons are destroyed (as in narcolepsy), people experience uncontrollable sleepiness.
Common Questions
Safety Information
Common Side Effects
Cautions
- • Not FDA-approved
- • Very limited human safety data
- • May affect blood pressure and heart rate
What We Don't Know
Human safety profile is not well-established. Most data comes from animal studies and the inverse pharmacology of orexin receptor antagonists (sleep drugs like suvorexant).
Published Research
33 studiesExploring the role of Orexin-A neuropeptide in Parkinson's disease: A systematic review and meta-analysis
Changes in biochemical markers following a spinal manipulation - a systematic review update
Cerebrospinal fluid orexin in Alzheimer's disease: a systematic review and meta-analysis
Orexin-A in Patients With Lewy Body Disease: A Systematic Review and Meta-Analysis
Associations of plasma hypocretin-1 with metabolic and reproductive health: Two systematic reviews of clinical studies
Metabolic and Orexin-A Responses to Ketogenic Diet and Intermittent Fasting: A 12-Month Randomized Trial in Adults with Obesity
Effects of different doses of dexmedetomidine combined with stellate ganglion block in patients undergoing laparoscopic radical resection of colorectal cancer
Propofol versus sevoflurane anesthesia on postoperative sleep quality in older patients after major abdominal surgery: A randomized clinical trial
The Effect of Digital Addiction Training on University Students' Digital Addiction, Sleep Quality, and Orexin-A Levels: Randomized Controlled Trial
Influence of Intermittent Fasting on Body Composition, Physical Performance, and the Orexinergic System in Postmenopausal Women: A Pilot Study
Safety and pharmacodynamics of a single infusion of danavorexton in adults with idiopathic hypersomnia
Intranasal orexin A modulates sympathetic vascular tone: a pilot study in healthy male humans
The effect of β-caryophyllene on food addiction and its related behaviors: A randomized, double-blind, placebo-controlled trial
Acute assessment of subjective appetite and implicated hormones after a hypnosis-induced hallucinated meal: a randomized cross-over pilot trial
The immediate effects of cervical spine manipulation on pain and biochemical markers in females with acute non-specific mechanical neck pain: a randomized clinical trial
[Impacts of the repetitive transcranial acupuncture stimulation on the content of serum orexin A in patients with post-stroke insomnia]
Plasma orexin A levels in recently menopausal women during and 3 years following use of hormone therapy
Inverse Association of Peripheral Orexin-A with Insulin Resistance in Type 2 Diabetes Mellitus: A Randomized Clinical Trial
Glucagon regulates orexin A secretion in humans and rodents
The effect of intranasal orexin-A (hypocretin-1) on sleep, wakefulness and attention in narcolepsy with cataplexy
Changes in biochemical markers of pain perception and stress response after spinal manipulation
Influence of season and nutritional status on the direct effects of leptin, orexin-A and ghrelin on luteinizing hormone and growth hormone secretion in the ovine pituitary explant model
Acute effects of different glycemic index diets on serum motilin, orexin and neuropeptide Y concentrations in healthy individuals
Effects of intranasal hypocretin-1 (orexin A) on sleep in narcolepsy with cataplexy
Olfactory dysfunction in patients with narcolepsy with cataplexy is restored by intranasal Orexin A (Hypocretin-1)
Circulating Concentrations of Orexin A Predict Left Ventricular Myocardial Remodeling
Evaluating Crossbred Red Rice Variants for Postprandial Glucometabolic Responses: A Comparison with Commercial Varieties
Migraine preventive drug-induced weight gain may be mediated by effects on hypothalamic peptides: the results of a pilot study
Plasma orexin A increases at emergence from sevoflurane-fentanyl anesthesia in patients undergoing ophthalmologic surgery
Hypocretin (orexin) deficiency in narcolepsy and primary hypersomnia
Oral Orexin Receptor 2 Agonist in Narcolepsy Type 1
Narcolepsy and the hypocretin system--where motion meets emotion
Orexin Deficiency in Narcolepsy: Molecular Mechanisms, Clinical Phenotypes, and Emerging Therapeutic Frontiers
Always consult a qualified clinician
This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician
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Quick Facts
- Class
- Neuropeptide
- Evidence
- Emerging
- Safety
- Limited Data
- Updated
- Mar 2026
- Citations
- 33PubMed
Also known as
Tags
Related Goals
Evidence Score
Clinical Trials
View Clinical TrialsLinks to ClinicalTrials.gov for reference. Listing does not imply endorsement.
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