SAN FRANCISCO—Oxytocin, often called "the love hormone," may play a protective role in mood disturbances triggered by sleep loss and hormonal shifts during key reproductive transitions like postpartum and menopause, according to a study being presented Saturday at ENDO 2025, the Endocrine Society's annual meeting in San Francisco, Calif.
Researchers at Brigham and Women's Hospital and Harvard Medical School studied the combined impact of sleep interruption and estrogen suppression on mood and oxytocin levels in healthy premenopausal women. Their findings suggest that oxytocin may help reduce the negative mood effects brought on by fragmented sleep, which is an often-overlooked consequence of reproductive transitions.
"We found that oxytocin levels rise in response to stress-related sleep disruption, and that women with higher oxytocin levels before disrupted sleep experienced less mood disturbance the next day," said Irene Gonsalvez, M.D., associate psychiatrist at Brigham and Women's Hospital and instructor at Harvard Medical School in Boston, Mass. "These results point toward oxytocin as a potential biological buffer during periods of hormonal and emotional vulnerability."
Women frequently experience disrupted sleep during the postpartum and menopausal periods that are associated with sharp hormonal fluctuations. Yet these disturbances are often minimized or seen as routine inconveniences. The study provides new biological evidence that such sleep interruptions are linked to meaningful changes in emotional health, and that oxytocin may serve as an important protective factor.
In the study, 38 healthy premenopausal women completed two 5-night inpatient protocols: one during a natural hormonal state and another after estradiol suppression. After two nights of uninterrupted sleep, researchers fragmented participants' sleep for three nights to simulate patterns commonly experienced during postpartum and menopause. Mood disturbance and oxytocin levels were assessed throughout.
Findings indicated that sleep interruption significantly increased both mood disturbance and oxytocin levels, and that higher oxytocin levels before sleep disruption were linked to reduced mood disturbance the following day. Higher incidences of mood disturbance associated with sleep disruptions were also linked to increased oxytocin levels the next day.
"Millions of women struggle with mood symptoms during reproductive transitions, yet treatments often focus narrowly on antidepressants or hormone therapy," Gonsalvez said. "Understanding oxytocin's potential as a natural mood modulator could help us better support women's mental health during these times."
This research was supported by the Brigham and Women's Hospital Connors Center WHISPR Award, the Dupont-Warren HMS Research Fellowship, and the National Institute on Aging.
