The study aims to explore the effects of Sumatriptan on Levcromakalim-induced migraine in individuals with migraine without aura.

Opening of adenosine triphosphate-sensitive potassium (KATP) channels using Levcromakalim causes migraine attacks with and without aura in a high proportion of patients.

Sumatriptan has been shown to reverse Levcromakalim-induced dilation of the middle meningeal artery and headache in healthy volunteers, indicating that Sumatriptan can overturn the physiological effects of levcromakalim.

The study aims to explore the effects of Sumatriptan on Levcromakalim-induced migraine in individuals with migraine without aura.

Inclusion Criteria:

1. Participant has provided informed consent prior to initiation of any study-specific activities/procedures.
2. Age ≥18 years upon entry into screening.
3. History of migraine without aura for ≥12 months with a frequency of 1-5 migraine attacks per month before screening according to the International Headache Society (IHS) Classification ICHD-3 (Headache Classification Committee of the International Headache Society, 2018), based on medical records and/or patient self-report.

Exclusion Criteria:

1. History of any primary headache disorder other than migraine without aura, or tension-type headache with a frequency of ≥5 headache days per month before screening according to the International Headache Society (IHS) Classification ICHD-3 (Headache Classification Committee of the International Headache Society, 2018), based on medical records and/or patient self-report.
2. History of any secondary headache disorder before screening according to the International Headache Society (IHS) Classification ICHD-3 (Headache Classification Committee of the International Headache Society, 2018) based on medical records and/or patient self-report.
3. Any headache 48 hours prior to, or any migraine 72 hours prior to the start of the experiment on day 1 and 2.
4. Daily consumption of any drug/medication other than oral contraception (birth control).
5. Intake of prophylactic migraine medication within ≤30 days or 5 plasma half-lives (whichever is longer) prior to screening.
6. The participant is at risk of self-harm or harm to others as evidenced by past suicidal behavior.
7. History or evidence of any other clinically significant disorder, condition, or disease (with the exception of those outlined above) that, in the opinion of the investigator will pose a risk to participant safety or interfere with the study evaluation, procedures or completion.
8. Female participants of childbearing potential with a positive pregnancy test assessed at screening or day 1 by a urine pregnancy test.
9. Female participants who are pregnant or breastfeeding or plan to become pregnant or breastfeed during participation in the study.
10. Evidence of current pregnancy or breastfeeding per participant self-report or medical records.
11. Participants likely to not be available to complete all protocol-required study visits or procedures, and/or to comply with all required study procedures to the best of the participants' and investigator's knowledge.