Effects of substance P on headache induction and arterial dilation in healthy adults

What Was Tested

The paper reports a study of Substance P, published as a randomized controlled trial.

The primary endpoint was the incidence of headache within 12 hours after the infusion.

Other endpoints included the area under the curve (AUC) for headache intensity scores over the 12-hour observation period and AUC changes in the superficial temporal artery (STA) diameter from baseline to 120 minutes post-infusion.ResultsTwenty-one participants underwent randomization and completed both experiment days.

Who Took Part

According to the abstract, 21 participants were involved.

By PubMed's age tags, the people studied were young adults, adults and middle-aged adults, both men and women.

How the Study Was Run

In design terms this was a randomized, double-blind, placebo-controlled and crossover study.

Because people in this Substance P study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Blinding on both sides kept the participants and researchers unaware of who received Substance P.

The comparison arm used a placebo, so changes seen with Substance P could be set against what happens without it.

Each person switched between Substance P and the comparison at some point, usually with a gap in between.

What Was Measured

The primary endpoint was the incidence of headache within 12 hours after the infusion.

Other endpoints included the area under the curve (AUC) for headache intensity scores over the 12-hour observation period and AUC changes in the superficial temporal artery (STA) diameter from baseline to 120 minutes post-infusion.ResultsTwenty-one participants underwent randomization and completed both experiment days.

Topics PubMed links to this paper include Substance P, Headache, Vasodilation, Temporal Arteries and Healthy Volunteers.

Author keywords: migraine, provocation and trigeminovascular system.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Substance P in 21 participants.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2025 (Cephalalgia : an international journal of headache), a journal based in England.

More context: the Substance P compound page, all human trials.