A meta-analytic review of the impact of intranasal oxytocin administration on cortisol concentrations during laboratory tasks: moderation by method and mental health.
Level 1 - systematic review of randomized trials
Meta-analysis of 18 randomized placebo-controlled trials
PubMed 25086828 · doi:10.1016/j.psyneuen.2014.07.014
What was done
Authors conducted a random-effects meta-analysis of 18 randomized, placebo-controlled studies (k = 18, N = 675) evaluating the acute effect of intranasal oxytocin administration on cortisol responses to laboratory tasks. Moderator analyses tested the effects of task challenge level (robust HPA-axis stimulation vs. not) and participant status (clinical populations vs. healthy controls), controlling for baseline cortisol concentrations.
What was found
The overall effect of intranasal oxytocin on cortisol response was non-significant (Hedges g = -0.151, p = 0.11; I² = 31%). In moderator analyses controlling for baseline cortisol, oxytocin significantly reduced cortisol responses during tasks that robustly stimulated the HPA axis (Hedges g = -0.433, 95% CI [-0.841, -0.025]) and in clinical populations compared to healthy controls (Hedges g = -0.742, 95% CI [-1.405, -0.078]).
Why it matters
These results indicate that intranasal oxytocin does not uniformly blunt cortisol but acts selectively during potent stress challenges and in individuals with psychiatric conditions, helping clarify mixed findings in human stress-regulation research.
Limits
The total sample size across 18 studies was small (N = 675, averaging ~37 participants per study), resulting in wide confidence intervals in subgroup analyses. The study evaluated only acute laboratory tasks rather than real-world stress or repeated dosing.
Cited by
- partial Oxytocin actively lowers cortisol levels in the human body.