Plasma oxytocin concentrations following MDMA or intranasal oxytocin in humans

This double-blind trial (n=14) compared the effects of MDMA (52.5-105 mg/70kg), intranasal oxytocin (20 IU or 40 IU), and placebo on plasma oxytocin concentrations. MDMA (105 mg/70kg only) increased plasma oxytocin levels to a mean peak of 83.7 pg/ml at approximately 90–120 min compared to a 48.0 pg/ml, 30–60 min increase after oxytocin administration.

Abstract

“MDMA (±3,4-methylenedioxymethamphetamine, ‘ecstasy’) is reportedly used recreationally because it increases feelings of sociability and interpersonal closeness. Prior work suggests that the pro-social effects of MDMA may be mediated by the release of oxytocin. A direct examination of plasma levels of oxytocin after acute doses of oxytocin and MDMA in the same individuals would provide further evidence for the idea that MDMA produces its pro-social effects by increasing oxytocin. Fourteen healthy MDMA users participated in a 4-session, double-blind study in which they received oral MDMA (0.75 and 1.5 mg/kg), intranasal oxytocin (20 IU or 40 IU), and placebo. Plasma oxytocin concentrations, as well as cardiovascular and subjective effects, were assessed before and at several time points after drug administration. MDMA (1.5 mg/kg only) increased plasma oxytocin levels to a mean peak of 83.7 pg/ml at approximately 90–120 min, compared to 18.6 pg/ml after the placebo. Intranasal oxytocin (40 IU, but not 20 IU) increased plasma oxytocin levels to 48.0 pg/ml, 30–60 min after nasal spray administration. MDMA dose-dependently increased heart rate, blood pressure, feelings of euphoria (e.g., ‘High’ and ‘Like Drug’), and feelings of sociability, whereas oxytocin had no cardiovascular or subjective effects. The subjective and cardiovascular responses to MDMA were not related to plasma oxytocin levels, although the N was small for this analysis. Future studies examining the effects of oxytocin antagonists on responses to MDMA will help to determine the mechanism by which MDMA produces pro-social effects.”

Authors: Matthew Kirkpatrick, Sunday M. Francis, Royce Lee, Harriet de Wit & Suma Jacob

Study details

Compounds studied
MDMA

Topics studied
Neuroscience

Study characteristics
Placebo-Controlled Double-Blind Within-Subject

Participants
14 Humans

Authors

Authors associated with this publication with profiles on Blossom

Harriet de Wit
Harriet de Wit is a Professor of Psychiatry and Behavioral Neuroscience at the University of Chicago. Her research focuses on the physiological, subjective (i.e., mood-altering), and behavioral effects of drugs in healthy human volunteers.

Compound Details

The psychedelics given at which dose and how many times

MDMA 52.5 - 105
mg | 1x

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