Objective: To investigate whether levcromakalim (a K ATP channel opener) induces migraine-like headache in people with persistent post-traumatic headache who had no known history of migraine., Methods: In a randomized, double-blind, placebo-controlled, 2-way crossover trial, participants were randomly assigned to receive a 20-minute continuous intravenous infusion of levcromakalim (50 µg/mL) or placebo (isotonic saline) on two separate experimental days with a 1-week wash-out period in between. The primary endpoint was the difference in incidence of migraine-like headache between levcromakalim and placebo during a 12-hour observational period after infusion start. The secondary endpoint was the difference in area under the curve for baseline-corrected median headache intensity scores between levcromakalim and placebo during the 12-hour observational period., Results: A total of 21 participants with persistent post-traumatic headache were randomized and completed the trial. During the 12-hour observational period, 12 (57%) of 21 participants reported experiencing migraine-like headache following the levcromakalim infusion, compared with three after placebo ( P = 0.013). Moreover, the baseline-corrected median headache intensity scores were higher following the levcromakalim infusion than after placebo ( P = 0.003)., Conclusion: Our findings suggest that K ATP channels play an important role in the pathogenesis of migraine-like headache in people with persistent post-traumatic headache. This implies that K ATP channel blockers might represent a promising avenue for drug development. Further research is warranted to explore the potential therapeutic benefits of K ATP channel blockers in managing post-traumatic headache. Trial Registration : ClinicalTrials.gov Identifier: NCT05243953., Competing Interests: Declaration of conflicting interestsThe authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: DWD. reports the following competing interests. Consulting: Amgen, Atria, CapiThera Ltd., Cerecin, Ceruvia Lifesciences LLC, CoolTech, Ctrl M, Allergan, AbbVie, Biohaven, GlaxoSmithKline, Lundbeck, Eli Lilly, Novartis, Impel, Satsuma, Theranica, WL Gore, Genentech, Nocira, Perfood, Praxis, AYYA Biosciences, Revance, Pfizer. Honoraria: American Academy of Neurology, Headache Cooperative of the Pacific, Canadian Headache Society, MF Med Ed Research, Biopharm Communications, CEA Group Holding Company (Clinical Education Alliance LLC), Teva (speaking), Amgen (speaking), Eli Lilly (speaking), Lundbeck (speaking), Pfizer (speaking), Vector Psychometric Group, Clinical Care Solutions, CME Outfitters, Curry Rockefeller Group, DeepBench, Global Access Meetings, KLJ Associates, Academy for Continued Healthcare Learning, Majallin LLC, Medlogix Communications, Medica Communications LLC, MJH Lifesciences, Miller Medical Communications, WebMD Health/Medscape, Wolters Kluwer, Oxford University Press, Cambridge University Press. Non-profit board membership: American Brain Foundation, American Migraine Foundation, ONE Neurology, Precon Health Foundation, International Headache Society Global Patient Advocacy Coalition, Atria Health Collaborative, Arizona Brain Injury Alliance, Domestic Violence HOPE Foundation/Panfila. Research support: Department of Defense, National Institutes of Health, Henry Jackson Foundation, Sperling Foundation, American Migraine Foundation, Henry Jackson Foundation, Patient Centered Outcomes Research Institute (PCORI). Stock options/shareholder/patents/board of directors: Aural analytics (options), Axon Therapeutics (shares/board), ExSano (options), Palion (options), Man and Science, Healint (options), Theranica (options), Second Opinion/Mobile Health (options), Epien (options), Nocira (options), Matterhorn (shares), Ontologics (shares), King-Devick Technologies (options/board), EigenLyfe (shares), AYYA Biosciences (options), Cephalgia Group (shares/board), Atria Health (options/employee). Patent 17189376.1-1466:vTitle: Onabotulinum Toxin Dosage Regimen for Chronic Migraine Prophylaxis (Non-royalty bearing). Patent application submitted: Synaquell® (Precon Health). In addition, R.B. has received honoraria, acted as a consultant or advisory board member for Alder, Allergan, Amgen, Autonomic Technologies, Avanir, Biohaven, CGRP Diagnostics, Dr. Reddy's Laboratories, ElectroCore, Eli Lilly, GlaxoSmithKline, Merck, Pernix, Teva, and Trigemina. RB also reports receiving CME fees from Healthlogix, Medlogix, and WebMD/Medscape, and holds patents for several products, including (9061025, 11732265.1, 10806890, US2021-0015908, WO21007165, US2021-0128724, WO21005497). RB is a reviewer for the National Institute of Neurological Disorders and Stroke (NINDS) and holds stock options in Allay Lamp and Percept, outside of the submitted work. HA reports personal fees from Teva, outside of the submitted work. HMA reports personal fees from Pfizer, outside of the submitted work. The remaining authors declare no competing interests.