Orexin Blockers

Try cognitive behavioural therapy for insomnia (CBT-I) first. If you need a pill for more than a few weeks, an orexin blocker is a reasonable choice — but expect a small effect, know that sleep paralysis and daytime sleepiness are more likely than on a placebo, and remember they are still controlled drugs.

What they are

Orexin is a brain chemical that keeps you awake. The three drugs in this class block both of its receptors, which is why doctors call them dual orexin receptor antagonists, or DORAs. Instead of switching on sedation, as benzodiazepines and Z-drugs do, they turn down the signal that holds you awake.^[1]

The guidelines put any sleeping pill second to CBT-I for chronic insomnia; see Treating chronic insomnia for when a pill makes sense at all.

They work, but the effect is small

Pooling 8 randomised trials and about 5,200 adults, all three drugs beat placebo on falling asleep, staying asleep and insomnia severity. The effects were small — in the range where a statistically clear result is not necessarily one a patient would notice — and the trials lasted only one to six months.^[2]

The largest comparison of sleeping pills, pooling 170 randomised trials of 36 treatments, is less flattering. It found sustained benefit beyond placebo for only two drugs, lemborexant and the Z-drug eszopiclone. It grouped daridorexant and suvorexant with the benzodiazepines on how well people tolerated them, and judged the long-term safety data for lemborexant inconclusive.^[3]

The real advantage: no rebound when you stop

In trials of up to six months, stopping an orexin blocker abruptly showed no sign of tolerance, withdrawal or rebound insomnia.^[4] That is a real advantage over benzodiazepines and Z-drugs, and the main reason this class is usually preferred when a pill is needed.

They are not free of abuse potential. All three are Schedule IV controlled substances in the US, because people who use sedatives recreationally report measurable drug-liking on them. In one such study, daridorexant at its prescribed dose produced less drug-liking than an above-normal dose of zolpidem (though still more than placebo),^[5] and postmarketing surveillance suggests the class carries less abuse risk than the older sleeping pills.^[6] Lower risk than a benzodiazepine, then — not a drug with no controls on it at all.

Side effects that look like narcolepsy

The class's distinctive side effects resemble narcolepsy, the disorder of sudden, uncontrollable sleep. Pooling 11 randomised trials and 7,703 patients, orexin blockers roughly tripled the risk of sleep paralysis and roughly doubled excessive daytime sleepiness compared with placebo, alongside a small (about 9%) excess of side effects overall.^[7]

These events are uncommon, so the estimates are imprecise: for both sleep paralysis and daytime sleepiness, the lower end of the plausible range sits close to no increase at all. But the direction is consistent.

Fractures: unresolved

The preference for orexin blockers rests mostly on the absence of the harms Z-drugs and benzodiazepines are known for, not on evidence that they are safer on hard outcomes. The fracture data point both ways. One matched study found more hip fractures on suvorexant than on a Z-drug or benzodiazepine,^[8] while a meta-analysis of over 46,000 people found no excess of falls or fractures.^[9]

This is a newer class with less long-term data, not a proven safer one. Missing evidence of harm is not the same as evidence of no harm.

What to do

1. Start with CBT-I. It outlasts any pill; a pill is for when it has failed, for a short crisis, or as a bridge while it starts.
2. If you need a pill for more than a few weeks, an orexin blocker (or very low-dose doxepin) is the usual choice, including for older adults — for fewer known harms rather than proven safety.
3. Expect a modest gain, not a transformed night.
4. Know the side effects: sleep paralysis and heavy daytime sleepiness are uncommon but more likely than on placebo.
5. Treat it as a controlled drug, with less abuse potential than a Z-drug or benzodiazepine but not none.

For the older pills these are compared against, see Z-drugs.

Further reading

• Kishi T et al. Comparative efficacy and safety of daridorexant, lemborexant, and suvorexant for insomnia: a systematic review and network meta-analysis. Transl Psychiatry 2025.^[10]
• Na HJ et al. Clinical safety and narcolepsy-like symptoms of dual orexin receptor antagonists in patients with insomnia: a systematic review and meta-analysis. Sleep 2024 — 11 RCTs, 7,703 patients.^[11]
• De Crescenzo F et al. Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a systematic review and network meta-analysis. Lancet 2022 — 170 trials, 36 interventions.^[12]
• Ufer M et al. Abuse potential assessment of the new dual orexin receptor antagonist daridorexant in recreational sedative drug users as compared to suvorexant and zolpidem. Sleep 2022.^[13]
• Moline M et al. The abuse potential of lemborexant, a dual orexin receptor antagonist, according to the 8 factors of the Controlled Substances Act. Psychopharmacology 2023.^[14]
• Pan G et al. Association between the use of orexin receptor antagonists and falls or fractures: A meta-analysis. J Psychiatr Res 2024.^[15]
• Żełabowski K et al. Targeting the Orexin System in the Pharmacological Management of Insomnia and Other Diseases: Suvorexant, Lemborexant, Daridorexant, and Novel Experimental Agents. Int J Mol Sci 2025.^[16]