Double-blind, randomised, placebo-controlled crossover study (n=30) testing oral LSD pulse regimen (3 × 100 µg over 3 weeks) versus placebo in patients with cluster headache.
This double-blind, randomised, placebo-controlled two-phase crossover trial tests whether a pulse regimen of oral LSD (three 100 µg doses across three weeks) reduces frequency and intensity of cluster headache attacks compared with placebo.
Primary outcomes are changes in attack frequency and intensity recorded in a standardised headache diary; safety and tolerability are monitored throughout. Eligibility includes adults 25–75 years with chronic or predictable episodic cluster headache responsive to oxygen.
Oral LSD pulse regimen (3 × 100 µg over 3 weeks); crossover sequence (LSD then placebo or placebo then LSD).
Pulse regimen: 100 µg per dose, three doses across three weeks.
Identical-looking placebo vials administered in same schedule as LSD; crossover sequence.
Placebo in identical-looking vial, three doses across three weeks.