A Phase 2 interventional study of Oxytocin nasal spray and Placebo nasal spray in Cold Exposure, sponsored by Florida Institute for Human and Machine Cognition. Completed at 2 sites in United States. Open to male participants aged 18 Years to 39 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by Florida Institute for Human and Machine Cognition · Phase 2, Interventional, and Prevention
Naval Special Warfare (NSW) operators are exposed to a variety of extreme environmental conditions and intense physical demands. In addition to breathing high pressure gases at depth, prolonged cold water immersion and inadequate recovery from sustained physical exertion negatively impact individual and team performance. Biotechnologies that could mitigate the effects of cold as well as support physical recovery represent a significant unmet need for the NSW operational community.
Oxytocin (OT) has a wide range of actions both locally in the brain and peripherally in the body including skeletal muscle. These peripheral effects can be mediated by classic ligand-receptor activation given the abundant expression of the oxytocin receptor in peripheral tissues, along with local expression of OT in peripheral tissues where it is likely to act in an autocrine manner. Exogenous OT via intranasal administration is FDA Investigational New Drug (IND)-approved and has been demonstrated as an easy and safe method to increase circulating OT concentrations that may augment actions on peripheral tissues.
Naval Special Warfare (NSW) operators are exposed to a variety of extreme environmental conditions and intense physical demands. In addition to breathing high pressure gases at depth, prolonged cold water immersion and inadequate recovery from sustained physical exertion negatively impact individual and team performance. Biotechnologies that could mitigate the effects of cold as well as support physical recovery represent a significant unmet need for the NSW operational community.
Oxytocin (OT) has a wide range of actions both locally in the brain and peripherally in the body including skeletal muscle. These peripheral effects can be mediated by classic ligand-receptor activation given the abundant expression of the oxytocin receptor in peripheral tissues, along with local expression of OT in peripheral tissues where it is likely to act in an autocrine manner. Exogenous OT via intranasal administration is FDA Investigational New Drug (IND)-approved and has been demonstrated as an easy and safe method to increase circulating OT concentrations that may augment actions on peripheral tissues.
Cold water operators undergo an extensive and unique set of physical, physiological, and psychological stressors during a mission. In-water transit may exceed 6 hours submerged in cold water, on rebreathers, and in a confined space. During this lengthy transit, operators must maintain vigilance over navigation, vehicle, and life support controls while exposed to the risks of mixed gas or oxygen rebreather diving, alongside hypothermia, dehydration, undernutrition, and other factors that can significantly degrade operator performance. Once the team has reached target, they must be at peak cognitive and physical readiness as they carry out their mission objective. When the mission objective is complete, the operators undertake the lengthy return trip back to their deployed base. Optimized operator cognitive and physical performance is essential throughout all phases of a cold water mission, and safe and tolerable approach to optimizing warfighter performance and resilience will be key for future cold water operations.
Given the potential thermogenic and recovery effects or intranasal OT, we hypothesize that prophylactic OT administration, compared to placebo, will mitigate deficits in mission-relevant performance during and after cold water exposure. For this project we will utilize the ONR Cold Water Performance Task Battery, which was designed based on results from a task analysis combined with input from the cold water operator community. The task battery has been validated for its ability to induce changes in core and peripheral body temperature, manual dexterity, cognitive performance, and physical performance following cold water exposure. Our hypothesis will be tested via one specific aim enrolling N=24 18-39 y/o men by using a rigorous, double-blind, placebo- controlled, within-subjects randomized cross-over trial comparing 48 IU OT vs placebo (saline) in cold water performance and recovery.
Specific Aim 1. To investigate the impact of intranasal OT on cold water task performance and recovery using the ONR Cold Water Performance Task Battery, which includes cold water exposure; cognitive performance testing via oculometric assessment and the Defense Automated Neurobehavioral Assessment (DANA); and physical performance testing via a simulated ruck, ladder climb, and manual dexterity testing.
Exclusion Criteria:
Single dose of intranasal oxytocin (48 IU) prior to testing protocol.
Drug: Oxytocin nasal spray
Single dose of intranasal treatment with placebo (identical to oxytocin nose spray minus the oxytocin)
Drug: Placebo nasal spray
Intranasal treatment with oxytocin via nasal spray (48 IU per dose)
Also known as: Oxytocin
Intranasal treatment with placebo via nasal spray
Also known as: Placebo
Cognitive performance assessment score change (code substitution)
Changes in code substitution scores as measured by the Defense Automated Neurobehavioral Assessment (DANA). Data will be measured in milliseconds for response time.
Time frame: Within 3 hours post-treatment
Cognitive performance assessment score change (code substitution)
Changes in code substitution scores as measured by the Defense Automated Neurobehavioral Assessment (DANA). Data will be measured in number of correct or incorrect responses.
Time frame: Within 3 hours post-treatment
Cognitive performance assessment score change (reaction time)
Changes in choice reaction time scores as measured by the Defense Automated Neurobehavioral Assessment (DANA). Data will be measured in milliseconds for response time.
Time frame: Within 3 hours post-treatment
Cognitive performance assessment score change (reaction time)
Changes in choice reaction time scores as measured by the Defense Automated Neurobehavioral Assessment (DANA). Data will be measured in number of correct or incorrect responses.
Time frame: Within 3 hours post-treatment
Oculometric assessment score change (saccades)
Altered ocular response as measured by the I-Portal Portable Assessment System (i-PAS). Saccades will be monitored and counted throughout the duration of the assessment.
Time frame: Within 3 hours post-treatment
Oculometric assessment score change (blink rate)
Altered ocular response as measured by the I-Portal Portable Assessment System (i-PAS). Number of blinks will be counted through the course of the assessment.
Time frame: Within 3 hours post-treatment
Oculometric assessment score change (blink duration)
Altered ocular response in blink duration as measured by the I-Portal Portable Assessment System (i-PAS). Blink duration will be measured in milliseconds.
Time frame: Within 3 hours post-treatment
Reduced rating of perceived exertion (RPE) during physical assessment post-cold water exposure
Participants will signal on the Borg (6-20) scale for whole body and lower body exertion following their exposure to cold water. Lower on the scale signal a lower level of perceived physical exertion.
Time frame: Within 3 hours post-treatment
Difference in grip strength in cold water
During and after cold water exposure, participants will complete a grip strength assessment through the use of a hand dynamometer. Measurements will be taken in Newtons.
Time frame: Within 3 hours post-treatment
Difference in manual dexterity (underwater knot untying) in cold water
During and after cold water exposure, participants will complete a timed underwater knot untying and peg board time trial. Measurement will be recorded in seconds.
Time frame: Within 3 hours post-treatment
Difference in manual dexterity (underwater peg board assessment) in cold water
During and after cold water exposure, participants will complete a timed underwater peg board assessment time trial. Measurement will be recorded in seconds.
Time frame: Within 3 hours post-treatment
Plan to share: No
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Florida Institute for Human and Machine Cognition