Cluster Headache

The short version

●Cluster headache causes excruciating, strictly one-sided head pain around the eye or temple, in attacks lasting 15 minutes to 3 hours, often with tearing, nasal congestion, and restlessness.
●Attacks cluster in bouts and have a striking circadian and seasonal rhythm; the pain is so severe it is nicknamed the "suicide headache."
●It is a primary headache disorder, distinct from migraine, with its own treatments.
●First-line acute treatment is high-flow oxygen and injectable/nasal triptans; prevention uses verapamil, with galcanezumab and nerve blocks among the options.
●Ketamine is not a standard treatment; it has been studied only in refractory chronic cluster headache, with limited evidence.¹ ² ³
●This is a neurology-managed condition; ketamine here is investigational and not part of routine care.

Clinical definition

Cluster headache is a trigeminal autonomic cephalalgia characterized by attacks of severe, strictly unilateral orbital, supraorbital, or temporal pain lasting 15–180 minutes, accompanied by ipsilateral cranial autonomic features (lacrimation, conjunctival injection, nasal congestion, ptosis) and/or a sense of restlessness or agitation. Attacks occur from once every other day to eight times daily, often at the same time each day, in bouts (episodic) or without sustained remission (chronic). It is a primary headache disorder distinct from migraine, and among the most painful conditions in medicine.

How it differs from related conditions

vs. Migraine

Migraine attacks are usually longer, often bilateral or pulsating with nausea and light/sound sensitivity, and lack the clockwork autonomic, restless pattern of cluster.

vs. Trigeminal neuralgia

TN causes brief, electric-shock facial pains triggered by touch, distinct from cluster's longer autonomic attacks.

vs. Chronic pain

Cluster is a specific, episodic neurovascular pain disorder rather than a diffuse chronic pain syndrome.

First-line treatments

High-flow oxygen

A first-line acute treatment that aborts many attacks, with no systemic side effects.

Injectable/nasal triptans

Sumatriptan injection or nasal triptans abort attacks rapidly.

Verapamil (prevention)

The first-line preventive for cluster bouts, with cardiac monitoring.

Transitional/other options

Steroids or occipital nerve blocks as a bridge; galcanezumab for episodic cluster.

When standard treatments fail

For refractory chronic cluster headache, specialists consider greater occipital nerve blocks, CGRP-pathway treatment, neuromodulation (vagus nerve stimulation, sphenopalatine ganglion or occipital nerve stimulation), and, in research settings, agents such as ketamine. The evidence for ketamine here is limited to small studies and case series, so it sits at the refractory, specialist end of care.

Where ketamine fits

Cluster headache is not a condition Tovani treats, and ketamine is not a standard therapy for it. Interest exists because NMDA-receptor mechanisms contribute to pain processing, and small studies — an IV ketamine observational series and a ketamine-magnesium case series — have explored it in refractory chronic cluster headache, alongside systematic reviews of refractory-cluster treatment.¹ ² ³ But the evidence is limited and preliminary, and cluster headache is managed by neurologists with oxygen, triptans, verapamil, CGRP treatment, and neuromodulation. Anyone with cluster headache is best served in a headache or neurology clinic, where any role for ketamine would be considered only after standard options are exhausted.

Where this fits with Tovani

Tovani focuses on mood, anxiety, PTSD, and certain chronic pain conditions — cluster headache is a neurology-managed primary headache disorder outside that scope. If you have cluster headache, a headache specialist or neurologist is the right home: high-flow oxygen and triptans abort attacks, and verapamil and newer options prevent them. Ketamine for cluster is investigational and reserved for refractory cases in specialist settings. This page is here to point you to the care that helps.

Check eligibility Find treatment options The science behind ketamine

Frequently asked

Does ketamine treat cluster headache?

Not as standard care. It has been studied only in refractory chronic cluster headache in small studies and case series — limited, preliminary evidence. Cluster headache is treated by neurologists with oxygen, triptans, verapamil, and newer CGRP/neuromodulation options.

What stops a cluster headache attack fast?

High-flow oxygen and an injectable or nasal triptan (like sumatriptan) are the first-line acute treatments and can abort attacks quickly. Oral painkillers are too slow for the short, intense attacks.

Why is it called the "suicide headache"?

Because the pain is among the most severe in medicine and the despair during bouts can be profound. That severity is exactly why getting to a headache specialist for proper acute and preventive treatment matters. If you are having thoughts of suicide, call or text 988.

Does Tovani treat cluster headache?

No — it is a neurology-managed primary headache disorder outside our scope. A headache specialist or neurologist can offer the treatments that work. We would point you there rather than offer ketamine, which is investigational for cluster and reserved for refractory cases.

References

Membrilla JA et al. 2023, Journal of Neurology — Systematic review of preventive treatment for refractory chronic cluster headache. (PMID 36310189)
Moisset X et al. 2020, Headache — Ketamine-magnesium for refractory chronic cluster headache (case series). (PMID 33128280)
Granata L et al. 2016, Schmerz — Intravenous ketamine for cluster headache (observational study). (PMID 27067225)

Last reviewed by Dr. Ben Soffer, DO on June 2, 2026. This page is educational and not a substitute for clinical evaluation. A physician determines whether ketamine therapy is appropriate for your specific situation.