hypocretin

hormone

Also known as: orexin

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July 20, 2026

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Hypocretin, also known as orexin, is a chemical messenger crucial for maintaining alertness and stable sleep-wake cycles. Narcolepsy, a neurological condition, often arises when the brain loses its hypocretin supply. This loss is frequently attributed to an autoimmune response that damages specialized cells in the hypothalamus, which produce hypocretin.12

Narcolepsy can lead to overwhelming daytime drowsiness and sudden, irresistible sleep episodes. Individuals with narcolepsy may experience sleep paralysis and, in some cases, cataplexy, a sudden loss of muscle tone. Narcolepsy type 1 is characterized by the loss of hypocretin-producing neurons, while type 2 typically involves normal hypocretin levels and lacks cataplexy.2

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cataplexy
… of the brain that secrete hypocretin (orexin), which regulates wakefulness. The loss of hypocretin destabilizes the division of sleep and wake states, allowing muscle paralysis typical of REM sleep (rapid eye movement sleep) to occur while awake.
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… of the brain that secrete hypocretin (orexin), which regulates wakefulness. The loss of hypocretin destabilizes the division of sleep and wake states, allowing muscle paralysis typical of REM sleep (rapid eye movement sleep) to occur while awake.
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narcolepsy
…of a hormone known as hypocretin (also known as orexin), which promotes wakefulness. The loss of hypocretin may in turn be linked to an underlying autoimmune disorder in which immune cells target the hormone for destruction. In some persons, autoimmunity against hypocretin is suspected to occur as a result of…
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…of a hormone known as hypocretin (also known as orexin), which promotes wakefulness. The loss of hypocretin may in turn be linked to an underlying autoimmune disorder in which immune cells target the hormone for destruction. In some persons, autoimmunity against hypocretin is suspected to occur as a result of…
Read More