Effects of Substance P on Headache Induction in Healthy Individuals

What Was Tested

This registered not phased trial tested Substance P.

It had two arms (groups): Substance P (experimental) and Placebo (placebo comparator).

Substance P will be administered by intravenous infusion.

Placebo (isotonic saline) will be administered by intravenous infusion.

The registry classes the interventions as drug.

More on the Plan

Substance P is a vasoactive signaling molecule that belongs to the tachykinin family of peptides.

It is expressed in multiple cells, including primary afferents of the trigeminal ganglion that innervate the meninges and its arteries.

For this purpose, the researchers will conduct a randomized, double-blind, placebo-controlled, 2-way crossover trial.

Who Took Part

21 planned participants were the target.

It was open to people of any sex aged from 18 years up to 65 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Age 18 to 65 years of age upon entry into screening. A body weight of 50 to 100 kg. Provision of informed consent prior to initiation of any study-specific activities/procedures.

The full record lists 3 inclusion and 16 exclusion criteria; among the exclusions: any history of moderate to severe traumatic brain injury; any history of cardiovascular disease, including cerebrovascular diseases; any history of pulmonary disease.

How the Study Was Run

The set-up was randomized, crossover and quadruple-blind.

The participants were allocated by chance, so the Substance P group and the comparison group should start out alike.

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

Neither the participants nor the staff measuring them knew who was on Substance P, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2024-10-14 with completion listed for 2025-12-31.

It ran at 1 site in Denmark.

Its stated primary purpose is basic science.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Substance P in 21 people.

Its size is small, so on its own it can only give an early look.

Its status is not yet recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

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