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Daridorexant

Extensively Studied

Best-in-class dual orexin receptor antagonist for next-day cognition: 8-hour half-life clears before morning, preserves N3/REM sleep… | Pharmaceutical · Oral

Aliases (4)
Quviviq · ACT-541468 · Nemorexant (former code) · (S)-(2-(5-Chloro-4-methyl-1H-benzimidazol-2-yl)-2-methylpyrrolidin-1-yl)(5-methoxy-2-(2H-1,2,3-triazol-2-yl)phenyl)methanone
TYPICAL DOSE
25 mg dose
ROUTE
Oral (tablet)
CYCLE
Cycling not required
STORAGE
Room temp; original container
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Brand options2 known
QuviviqACT-541468

StatusSchedule IV (US DEA, effective 2022-04-07) | Class B/POM equivalent (EU, approved 2022-04) | Rx-only most jurisdictions

Overview TL;DR

Best-in-class dual orexin receptor antagonist for next-day cognition: 8-hour half-life clears before morning, preserves N3/REM sleep architecture (unlike Z-drugs/benzos), shows strongest total-sleep-time signal at 50 mg in 2025 NMA, and has no rebound insomnia or withdrawal through 12 months. For Dylan: WATCH-LIST not PRIMARY — his issue is a delayed chronotype, not insomnia, and DORAs lower wake drive but don't shift the circadian phase. Reserve as the escalation step if 4-6 weeks of l-tryptophan + magnesium + dim-light hygiene + 0.3-0.5 mg early-evening melatonin fails to migrate bedtime to midnight, OR if WASO/sleep maintenance becomes a real complaint after V5 modafinil onboarding stresses sleep.

Mechanism of action

Daridorexant is a competitive, reversible antagonist at both orexin receptors (OX1 and OX2) — a "DORA" in the modern nomenclature.

The orexin system in plain English: Orexin (also called hypocretin) is a hypothalamic neuropeptide that functions as the brain's "stay awake" master switch. Orexin neurons live in the lateral hypothalamus, fire vigorously during wakefulness, fall silent during sleep, and project broadly to every wake-promoting nucleus in the brain — locus coeruleus (norepinephrine), tuberomammillary nucleus (histamine), raphe (serotonin), VTA (dopamine), basal forebrain (acetylcholine). When orexin neurons fire, they keep all these wake systems online. When they shut up, sleep happens.

Two receptor subtypes:

  • OX1 (HCRTR1): preferential for orexin-A; concentrated in locus coeruleus → drives arousal/vigilance/sympathetic tone.
  • OX2 (HCRTR2): binds both orexin-A and orexin-B; concentrated in tuberomammillary nucleus → drives wakefulness/histamine cascade. OX2 blockade is the dominant sleep-promoting pathway; OX1 contributes secondary.

Why DORAs are mechanistically cleaner than GABAergic hypnotics:

  • Z-drugs (zolpidem) and benzos work by forcing GABA-A activation everywhere — including circuits that have nothing to do with sleep. Result: sedation that overrides normal sleep architecture, suppresses REM and N3 (deep) sleep, blunts memory consolidation, produces next-day cognitive impairment, and creates tolerance + dependence over weeks.
  • DORAs work by removing one input to the wake circuit — not by adding sedative pressure. The brain's endogenous sleep-promoting circuits (VLPO, melanin-concentrating hormone neurons, adenosine accumulation) then drive sleep on their own, with their own architecture. Sleep is "permitted" rather than "forced."

Daridorexant-specific features:

  • Half-life ~8 hours — deliberately designed to align with a normal sleep window. Suvorexant is 12 hr, lemborexant is 17-19 hr. The 8-hour half-life is daridorexant's central engineering claim: enough to last the night, gone by morning.
  • CYP3A4-dominant metabolism (~89% of clearance) — clinically relevant for stack design (see Drug Interactions).
  • No clinically meaningful active metabolites at therapeutic doses — clean PK profile.
  • Preserves sleep architecture in PSG studies (post-hoc analysis of phase 3 data, Sleep 2024): no alteration of N2/N3/REM EEG spectra, no change in sleep spindles, dose-dependent reduction in N1 (light, fragmented sleep) and increases in N2/N3/REM (consolidated, restorative sleep). This is the architecture profile a brain-priority user wants — most hypnotics suppress N3 and/or REM.

Idorsia development context: Idorsia Pharmaceuticals (Swiss spin-off from Actelion 2017) developed daridorexant after spending the late 2010s searching for an OX1/OX2 dual antagonist with a tight half-life window. ACT-541468 (later daridorexant) was selected from ~12,000 candidates specifically for the 8-hour half-life property. FDA approved 2022-01-07; DEA scheduled IV 2022-04-07; EMA approved 2022-04-29. Real-world EU rollout has been slower than anticipated, putting financial pressure on Idorsia (relevant if you care about long-term supply continuity).

Pharmacokinetics No data
Pharmacokinetics data not available for this compound.
No half-life mentions found in the source notes.
Research indications1 use cases

Half-life ~8 hours

Most effective

deliberately designed to align with a normal sleep window. Suvorexant is 12 hr, lemborexant is 17-19 hr. The 8-hour half-life is daridore…

Research protocols2 protocols
GoalDoseFrequencySoloCycle
Avoid food in the hour before25 mg doses (10 mg in the phase 3 trials) failed to separate from placebo on primary endpoints
PRN use is fine

Auto-extracted from dosing notes. For full context including caveats and Dylan-specific protocols, see the Dosing protocols section.

Quality indicators4 checks
FDA-approved manufacturer
NDC code on the bottle matches FDA registration. Generic OK; backyard not OK.
Brand vs generic listed
Pharmacy fills should disclose substitution. AB-rated generics are bioequivalent.
Tamper-evident packaging
Pharmacy seal intact, lot number + expiry visible on the bottle and the box.
!
Schedule labeling correct
C-II / C-IV warnings on label match the medication; report any mismatch to the pharmacist.
What to expect From notes
  1. 1
    Onset
    ~30-60 min to perceptible relaxation; Tmax ~1-2 hr (food delays Tmax modestly but doesn't change AUC meani…
  2. 2
    Peak
    ~1-3 hours after dose. The feel is "reduced wakefulness drive," not sedation. Most users describe it as: t…
Side effects + safety Tabbed view

Common (>10% users)

  • Headache — ~5-10% (lower than the 30%+ seen with modafinil). Usually fades within a week.
  • Somnolence / fatigue next-day — ~6% at 50 mg, ~4% at 25 mg. More likely in the first week. The 2025 Sleep Medicine paper actually showed less next-morning sleepiness vs placebo on average — but the individual variability matters.

Less common (1-10%)

  • Dizziness — ~2-3%, mostly first week.
  • Nausea — uncommon but reported.
  • Nasopharyngitis — most common TEAE in the 12-month extension (likely incidental, similar rate as placebo).
Interactions12 compounds
  • l-tryptophanSynergistic
    Tryptophan feeds the melatonin pathway (substrate-side), daridorexant lowers wake drive (receptor-side). They work on different mechanisms with non-overlappi…
  • Magnesium glycinateSynergistic
    (already V4): NMDA modulation + glycinergic relaxation. Mechanistically independent. Safe stack.
  • ApigeninSynergistic
    (already V4): GABA-A PAM at low doses. Theoretically additive but in practice neither produces strong sedation alone — combining is fine.
  • L-theanineSynergistic
    (already V4): GABA modulation + glutamate downregulation. Compatible.
  • AlcoholAvoid
    Phase 1 study (PMID 33205362) shows additive PD impairment (saccadic velocity, body sway, alertness). FDA labeling says don't combine. For Dylan zero-alcohol…
  • Strong CYP3A4 inhibitorsAvoid
    (clarithromycin, ketoconazole, itraconazole, ritonavir, nefazodone, grapefruit juice in large quantities): AVOID — daridorexant exposure can rise 4-5×. Label…
  • Moderate CYP3A4 inhibitorsAvoid
    (diltiazem, erythromycin, fluconazole, fluvoxamine, verapamil, ciprofloxacin): Maximum 25 mg dose. Don't titrate to 50 mg.
  • Strong CYP3A4 inducersAvoid
    (carbamazepine, phenytoin, rifampin, St. John's wort, efavirenz, apalutamide, enzalutamide): efavirenz alone reduced AUC by 61%. Daridorexant becomes ineffec…
  • Other CNS depressantsAvoid
    (benzos, Z-drugs, opioids, gabapentinoids, phenibut, GHB): additive sedation and respiratory risk. Don't double-stack hypnotics.
  • BromantaneAvoid
    (in V5 plan): not a hard contraindication but conceptually contradictory the same evening — bromantane upregulates dopamine synthesis (wake-supportive), dari…
  • ModafinilAvoid
    same calendar day: pharmacokinetically fine (modafinil is mostly cleared by CYP3A4 induction effects but doesn't significantly inhibit), but functionally red…
  • SelankAvoid
    same evening: mechanistically theta-rhythm modulation; shouldn't dangerous-stack but probably blunts daridorexant's sleep-permitting effect because Selank is…
References20 sources
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