the participant arrives at the study site after having agreed to take part. a brief medical interview is performed to confirm the history of migraine without aura and to ensure that no exclusion criteria are present.

baseline measurements such as blood pressure, heart rate and a description of usual headache patterns are recorded.

the participant is assigned by a computer system to receive either apremilast 30 mg or a placebo (lactose monohydrate). the assignment is unknown to the participant and to the staff who interact with her.

the participant swallows one film‑coated tablet containing either 30 mg of apremilast or a matching tablet that contains only lactose. the dose is taken once, with water, in the morning after the baseline assessment.

for the first 90 minutes after the tablet is taken, blood pressure, mean arterial pressure and heart rate are measured at regular intervals to detect any immediate physiological changes.

the participant remains at the study site or returns home and is asked to record any head pain that occurs during the next 12 hours. each episode is described with start time, intensity (using a numeric scale), and characteristics that allow classification as a migraine‑like attack or a non‑migraine headache.

throughout the 12‑hour observation period the participant notes any unwanted symptoms such as nausea, dizziness or other discomforts. these observations are reported to the study staff at the end of the period.

after the 12‑hour window the participant returns for a final check. the recorded data on headache intensity, frequency, vital signs and adverse events are reviewed and entered into the study database.

the participant is thanked for her contribution and no further study procedures are required.