Intranasal and Intravenous Oxytocin for Analgesia to Noxious Heat Pain

What Was Tested

This registered phase 2 trial tested Oxytocin.

Oxytocin will be given intravenously (IV) and as a nasal spray.

The study team also hopes to find out if the participants age, weight, or sex effects how well the study drug works.

It had two arms (groups): Intravenous (IV) oxytocin and intranasal (IN) placebo first (experimental) and Intravenous (IV) placebo and intranasal (IN) oxytocin first (experimental).

On Visit 2 participants will receive IV infusion of oxytocin. At the beginning of the IV infusion, the participant will self-administer IN placebo. On Visit 3 participants will receive IV infusion of placebo. At the beginning of the IV infusion, the participant will self-administer IN oxytocin..

On Visit 2 participant will receive IV infusion of placebo. At the beginning of the IV infusion, the participants will self-administer IN oxytocin. On Visit 3 participants will receive IV infusion of oxytocin. At the beginning of the IV infusion, the participant will self-administer IN placebo.

The registry classes the interventions as drug.

More on the Plan

Equal numbers of adult men and women; ages 18-55 will be recruited.

Participants will report to the research unit for three visits, 1) screening, informed consent, pregnancy test, and training to consistently rate pain from an FDA-approved device to test heat pain.

Pain score at the end of 5-minute skin heating will be compared using mathematical modeling of the time course of change in each individual and in the study population as a whole.

The effect, if any, on these models of participant age, sex, and weight will be explored.

Who Took Part

24 actual participants took part.

It was open to people of any sex aged from 18 years up to 75 years.

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

Examples of who could join: Male or female \> 18 and ≤75 years of age, Body Mass Index (BMI) \<40.

The full record lists 2 inclusion and 8 exclusion criteria; among the exclusions: recent (\<3 months) nasal surgery or chronic conditions requiring daily intranasal (in) medications; hypersensitivity to any ingredient in pitocin® (marketed preparation of oxytocin for parenteral injection); latex allergy.

How the Study Was Run

It was run as a randomized, crossover and triple-blind study.

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

In the crossover set-up each of the participants took both Oxytocin and the comparison in turn, acting as their own control.

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

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

It started in 2025-11-05 with completion listed for 2026-06-01.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

Researchers chose this as the main measure: Pain Scale Score - End of 5-minute Skin Heating (time frame: Baseline Up to Hour 4.5). Pain Scale Score - During Skin Heating (time frame: Minute 5 During Skin Heating).

It also tracked 4 secondary outcomes, for example Pain Scale Score - During Skin Heating, Pain Scale Score - During Skin Heating, Pain Scale Score - During Skin Heating and Pain Scale Score - During Skin Heating.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Oxytocin in 24 people.

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

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Oxytocin compound page, all human trials.